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The influence exerted by one animal or one group of animals on another can hardly be estimated until one of them leaves the pic ture. In an established animal community which might be said to be balanced, all groups are held in boimds by their enemies. Balanced animal communities can be found the world over, and we are... | {
"Header 1": "CHAPTER <sup>I</sup>",
"Header 2": "Balance in Nature",
"token_count": 592,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The values of the study of zoology may be placed in two classes: cultural and practical. There is hardly a field of endeavor in the realm of human activities which is not greatly influenced by zoology and biology generally. The study of philosophy, the formulation of our conception of religion, the comprehension of soc... | {
"Header 1": "CHAPTER <sup>I</sup>",
"Header 2": "Zoology as Related to Man",
"token_count": 1050,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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This brief chapter is organized to afford <sup>a</sup> slight preview of the works and lives of <sup>a</sup> selected few of the historic pioneers of zoology. This is not an attempt to give <sup>a</sup> complete history of the subject. The works of numerous pioneers in special fields are being con sidered throughout th... | {
"Header 1": "HISTORY OF ZOOLOGY",
"token_count": 2044,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Karl Ernst von Baer (1792-1876), <sup>a</sup> Russian biologist, is one who really established embryology as a field of study. His notable paper on the development of the chick was published in 1832. He established the "germ layer theory,\*' thus explaining the unfolding and differentiation of the various organs of t... | {
"Header 1": "HISTORY OF ZOOLOGY",
"token_count": 1720,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
#### Living- Matter, or Protoplasm
Little is known concerning the origin of living matter, or protoplasm, as it is called, but more and more is being learned about its nature, characteristics, structure, and activities. Living matter is ahvays active in some degree, and this activity attracted the atten tion of schol... | {
"Header 1": "PROTOPLASM AND THE CELL",
"token_count": 1485,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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To begin with, it may be said that this substance has a variable degree of fluidity under different conditions. The range of this variation may be from semisolid to semiliquid. It is viscid and gelatinous in consistency. It is more or less granular, nearly colorless, and more or less translucent; however, it is never p... | {
"Header 1": "PROTOPLASM AND THE CELL",
"Header 2": "General Characteristics of Protoplasm and the Material of the Cell",
"token_count": 455,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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In addition to the general characteristics, there may be mentioned and described briefly <sup>a</sup> number of important activities common to all protoplasm. These properties are:
- 1. Irritability, which refers to the capacity present in all protoplasm for responding to changes in environmental conditions, or exter... | {
"Header 1": "PROTOPLASM AND THE CELL",
"Header 2": "Fundamental Properties or Activities of Protoplasm",
"token_count": 396,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Protoplasm is a semifluid material which is heavier than water and somewhat more refractive to light. Its physical constitution is similar to glue or gelatin, rather than to crystalloids, such as sugar or ordinary table salt (sodium chloride). Instead of being in the form of a true solution like salt in water, it consi... | {
"Header 1": "PROTOPLASM AND THE CELL",
"Header 2": "Physical Nature of Protoplasm",
"token_count": 539,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Up to the present time, protoplasm has eluded complete and exact chemical analysis. Nevertheless the compounds of living matter are composed of several elements, many of them the most ordinary and abundant in the world. The list of elements necessary to make human protoplasm could be gathered in almost any locality on ... | {
"Header 1": "PROTOPLASM AND THE CELL",
"Header 2": "Chemical Nature of Protoplasm",
"token_count": 1429,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The quantity of protoplasm comprising a single cell varies within wide limits ; therefore cells vary greatly in size. The majority of cells, but not all of them, require considerable magnification to be seen. Certain of the single-celled blood parasites are about as small as any cells known. They are barely seen with o... | {
"Header 1": "PROTOPLASM AND THE CELL",
"Header 2": "Structure of a Typical Animal Cell",
"token_count": 2037,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Following this stage each "of the new chromosomes, resulting from this splitting or division, migrates along the spindle fibers toward its respective centriole, or pole. This period is the anaphase. These " half-chromosomes " each soon come to have two chromonemata, and they carry the chromatin material of the new cell... | {
"Header 1": "PROTOPLASM AND THE CELL",
"Header 2": "Structure of a Typical Animal Cell",
"token_count": 643,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The animals included in this group are usually said to be the first to have existed on earth and, therefore, they are considered the oldest. Being single-celled, they are usually referred to as the simplest known animals, although many of them are perhaps more complicated than numerous many-celled or metazoan forms bec... | {
"Header 1": "PHYLUM PEOTOZOA IN GENERAL",
"token_count": 2041,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Stentor, Halteria, and Bursaria are common fresh-water genera while Balantidnim (Fig. 389) is a parasite in the intestine of man and some other mammals, (c) Tlypotrichida possess cirri or structures formed by fusion of cilia ; these are found principally on the ventral side. The cell is flattened dorsoventrally and
!... | {
"Header 1": "PHYLUM PEOTOZOA IN GENERAL",
"token_count": 2044,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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*Eudorina*, a simple colony; *Pandorina*, within gelatinous envelope; *Ceratium*, a linear colony; *Carchesium*, stalked infusorian colony; *Codonosiga*, a stalked flagellate colony. (Drawn by Joanne Moore.)
of these forms only two cells adhere, but in others the cells may remain attached after many divisions, with t... | {
"Header 1": "PHYLUM PEOTOZOA IN GENERAL",
"token_count": 450,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Organisms, whether plant or animal, of all degrees of complexity respond to various kinds of stimuli. The important stimuli which call out immediate or direct response by the animal are light, bodily contact, chemical change, temperature, gravity, mechanical currents, and electric currents. The response to <sup>a</sup>... | {
"Header 1": "PHYLUM PEOTOZOA IN GENERAL",
"Header 2": "Tropisms and Animal Reaction",
"token_count": 351,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Man has not yet found <sup>a</sup> way or need to eat Protozoa directly as food material, although he does draw on it indirectly by a food
chain including water fleas, larger crustaceans, and fish. Too, the protozoans are not classed as predators on man as would be the lion, but many of them are parasites. Many disea... | {
"Header 1": "PHYLUM PEOTOZOA IN GENERAL",
"Header 2": "Economic Relations of Protozoa",
"token_count": 1607,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The most common species are Euglena viridis and Euglena gracilis which are found abundantly in fresh water. This genus is also quite well represented among marine animals ; many Euglenae possess chloroplastids which give them the possibility of photosynthesis. They are usually found living in the surface waters of pond... | {
"Header 1": "EUGLENA OF CLASS MASTIGOPHORA",
"Header 2": "Habitat and Characteristics",
"token_count": 384,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The food problem among Euglenae as a group is interesting from the biological standpoint. It seems that some Euglenae are able to ingest other small organisms through the mouth and cytopharynx
to be digested in a vacuole within the endoplasm; this has been called holozoic nutrition as typical of animals. E. viridis p... | {
"Header 1": "EUGLENA OF CLASS MASTIGOPHORA",
"Header 2": "Habitat and Characteristics",
"Header 3": "Food and Assimilation",
"token_count": 915,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The many kinds of Amoeba live in fresh water, marine water, soil, or as parasites in the fluids of the visceral organs of higher types of animals. Amoeda proteus may be collected in a variety of places where conditions of water, temperature, and organic food are favorable, such as debris from watering troughs, bottoms ... | {
"Header 1": "AMOEBA OF CLASS SABCODINA",
"Header 2": "Characteristics and Habitat",
"token_count": 1668,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The life history of the niajiy-celled animals to be studied later includes a series of changes from egg, through embryo state, to adult. In Amoeba the cycle is likely only partly known, because it
Fig. 35. -Diagram to show fission in amoeba. A, Beginning of the process; B, fission neari... | {
"Header 1": "AMOEBA OF CLASS SABCODINA",
"Header 2": "Reproduction and Life Cycle",
"token_count": 1670,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
This animal has been the subject of much study and the victim of considerable experimentation. Paramecium caudatum is probably the species most commonly studied. It is easily available and islarge in size, ranging between 0.2 and 0.3 mm. in length.
#### Characteristics and Habitat
Paramecium is an active, cigar-sha... | {
"Header 1": "PARAMECIUM OF CLASS INFUSORIA",
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"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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This species has two micronuclei and one macronucleus. At regular in tervals of about every forty or fifty generations, the macronucleus
Fig. 40.—Conjugation and subsequent divisions in paramecium, showing activities of the micronucleus. Circles are micronuclei and crescents are macronu... | {
"Header 1": "PARAMECIUM OF CLASS INFUSORIA",
"token_count": 866,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
All animals whose bodies consist of few or many cells functioning as a unit are called metazoans. In most respects the vital activities of Metazoa are similar to those of Protozoa. Since Metazoa are more or less like compound Protozoa with some degree of inter cellular differentiation, it is thought by many authorities... | {
"Header 1": "METAZOAN ORGANIZATION",
"token_count": 977,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The simpler Metazoa are composed of only two kinds of somatic cells. These cells are grouped according to kind in two layers. With advanced differentiation, a rather wide variety of cells has been produced.
A tissue is an organization of similar cells into <sup>a</sup> group or layer for the performance of <sup>a</su... | {
"Header 1": "METAZOAN ORGANIZATION",
"Header 2": "Cellular Organization",
"token_count": 2015,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Tracheae are found in insects, gills of various modifications in many aquatic Metazoa, and lungs in the terrestrial vertebrate forms ; accessory to the lungs are the nasal passages, pharynx, larynx, trachea, and bronchi.
- f. The Circulatory or Vascular System is a very extensive one consisting of the heart, arteries, ... | {
"Header 1": "METAZOAN ORGANIZATION",
"Header 2": "Cellular Organization",
"token_count": 1784,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Ontogeny refers to the development and life history of the indi vidual organism, produced sexually from the union of germ cells or gametes. This process is quite generally similar wherever it occurs, differing only in detail. Embryological development is an expression referring to the processes which occur during the e... | {
"Header 1": "METAZOAN ORGANIZATION",
"Header 2": "Metazoan and Ontogeny-",
"token_count": 2034,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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In other cases separate cells are shed from ectoderm or endoderm or both, or from an undifferentiated
portion to orgajiize as <sup>a</sup> distinct layer between the other two. The position of the mesoderm is external to the endoderm and internal to the ectoderm. It nearly encircles the endoderm. Sooner or later <sup... | {
"Header 1": "METAZOAN ORGANIZATION",
"Header 2": "Metazoan and Ontogeny-",
"token_count": 283,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
#### SPONGES
The name of this phylum, Porifera (p6 rif'er a), means ''porebearers," and this, these animals certainly are. This group is thought to be sort of an aberrant type with peculiar relations, but the group is often considered the simplest and lowest type of Metazoa, notwithstanding the presence of a simple m... | {
"Header 1": "PHYLUM PORIFERA",
"token_count": 1408,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Scypha coronata\* (Ellis and Solander) has been mistakenly called "grantia," the European form, by most textbooks for years. This is a commonly studied representative of the phylum. It is available and is also comparatively simple in structure. It is not as simple, however, as Leucosolenia.
#### Habitat and Behavior ... | {
"Header 1": "PHYLUM PORIFERA",
"Header 2": "THE SIMPLE SPONGE",
"token_count": 2051,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Many sponges are beneficial to man, and there are a few wliich are detrimental. Oysters and some other Mollusca are injured or destroyed by certain sponges which attach themselves to the mollusc's body or by others which bore through its shell and thus kill it.
Of positive importance, lesser items include the large f... | {
"Header 1": "PHYLUM PORIFERA",
"Header 2": "Economic Relations",
"token_count": 372,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The phylum name, Coelenterata (sel eu ter a'ta), means "hollow intestine," and all of the representatives bear this out by possess ing a single large cavity in the body. There is a single opening to this cavity, and it functions as both mouth and anus. There are two general types of coelenterates ; the polyp form and t... | {
"Header 1": "PHYLUM COELENTERATA",
"token_count": 479,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The phylum is divided into three classes, each with three or four orders.
Class Hydrozoa.—These are typical polyp forms, many of which produce medusae forms by budding. The group includes marine, colonial polyps, or hydroids, floating colonial hydroids, such as Portuguese man-of-war, one special gro"up of corals, som... | {
"Header 1": "PHYLUM COELENTERATA",
"Header 2": "Classification of the Phylum",
"token_count": 2032,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The types of polyps include : gastrozooids (nutritive or feeding), dactylozooids -with nests of nematocysts and having long tentacles (tactile and protective), gonozooids which are male, repro ductive zooids, and others which produce ova-bearing medusae. Swimming bells (nectocalyces) often occur just below the pneumato... | {
"Header 1": "PHYLUM COELENTERATA",
"Header 2": "Classification of the Phylum",
"token_count": 2025,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
66.—Diagrams to show the structure of the anthozoan, Metridium, (Courtesy of Pacific Biological Laboratories.)
Mature ova and spermia are discharged into tlie water of tlie cavity and escape through the mouth to unite in fertilization outside. The development includes cleavage and planula stages, before the new indiv... | {
"Header 1": "PHYLUM COELENTERATA",
"Header 2": "Classification of the Phylum",
"token_count": 626,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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#### Habitat and Behavior
Hydra (Chlorohydra) viridissima is likely the most common hydra of the Southwest. It is the small green hydra which is very active and has short tentacles. This species has the green color because of the presence of a unicellular alga, Chlorella vulgaris, in the endoderm cells. The plant use... | {
"Header 1": "PHYLUM COELENTERATA",
"Header 2": "HYDRA",
"token_count": 1639,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Another feature of the organization of this animal is the diploblastic structure which consists of two layers of cells or the germ layers surrounding an internal space, the gastrovoscular cavity or enteron. These are studied on stained sections. The outer one is the ectoderm, which is thinner and is composed of four ty... | {
"Header 1": "PHYLUM COELENTERATA",
"Header 2": "Internal Anatomy",
"token_count": 1984,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The neuroepithelial cells are distributed among the other cells of the germ layers. There is a greater abundance of them on the hypostome, basal disc, and tentacles than along the length of the column. The greatest concentration of these cells is in the hypostome around the mouth, which makes this region in a sense com... | {
"Header 1": "PHYLUM COELENTERATA",
"Header 2": "The Nervous System and Nervous Conduction",
"token_count": 1122,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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This is a group of exclusively marine animals, most of which are pelagic (float near the surface). There is a limited number that lives and moves about on the bottom. Ctenophora (te nof'6 ra comb-bearing), because of their similarity to coelenterates, are often classified as a class in this phylum. There are only twent... | {
"Header 1": "PHYLUM CTENOPHORA",
"token_count": 1025,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The representatives of Phylum Platyhelminthes (plat <sup>i</sup> hel min' thez, broad worm) are usually called flatworms and in many ways show considerable advance over the coelenterates. Some of the species are parasitic, and the remainder of them are free-living. The common fresh-water planaria is an example of the f... | {
"Header 1": "PHYLUM PLATYHELMINTHES",
"token_count": 2009,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The body is elongated, flat, broadly wedge-shaped at the anterior and tapering to a point at the posterior end. It is triplohlastic since the ectoderm, endoderm, and mesoderm are all differentiated and present in a clear-cut fashion for the first time in our studies so far. The symmetry is distinctly hilateral. In Plan... | {
"Header 1": "PHYLUM PLATYHELMINTHES",
"Header 2": "External Anatomy",
"token_count": 1922,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Sexually the individuals are hermaphroditic. The spermatozoa or male germ cells mature in the testes, then pass through the vasa efferentia and vasa deferentia, to the seminal vesicles where they
are stored in advance of copulation. Here they become organized into pockets known as *spermatophores*. The ova mature in ... | {
"Header 1": "PHYLUM PLATYHELMINTHES",
"Header 2": "Reproduction and Life History",
"token_count": 1109,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The planarians and other free-living flatworms are of practically no economic importance, but the phylum includes a large number of forms, principally Trematodes and Cestodes, which are parasitic in higher vertebrate animals, including man. Such groups as the intestinal flukes, liver flukes, lung flukes, blood flukes, ... | {
"Header 1": "PHYLUM PLATYHELMINTHES",
"Header 2": "Economic Relations of the Phylum",
"token_count": 254,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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This group is known as the unsegmented roundworms or thread worms. Some of the Nemathelmiuthes (nem a thel min'thez, threadworms) are free-living in soil, fresh water, and salt water; some are found living in plant tissues ; and others live in animal tissues as parasites. The majority of them are microscopic, but a few... | {
"Header 1": "PHYLUM NEMATHELMINTHES",
"token_count": 1871,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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This is one of the largest nematodes, females commonly reaching a length of from eight to fourteen inches and males averaging six
to twelve inches. Males are always more slender and have a curled tail instead of the blunt tail of the female. The mouth is guarded by three lips, two in lateroventral positions and one d... | {
"Header 1": "ASCARIS, A REPRESENTATIVE ROUNDWORM",
"Header 2": "External Anatomy",
"token_count": 868,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The animals copulate, and at this time the spermatozoa are intro duced into the vagina of the female to fertilize the mature ova in the oviducts. A mature female may contain as many as 27,000,000 eggs. These eggs pass from the host with the feces. Some workers have reported that each female worm in an infected host may... | {
"Header 1": "ASCARIS, A REPRESENTATIVE ROUNDWORM",
"Header 2": "Reproduction and the Life Cycle",
"token_count": 312,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
This is the name of a group composed of two classes, as they are treated here. It is usually considered a phylum name, but many authors prefer to give each of the classes phylum rank. The justification of the latter plan may be questionable.
Class Bryozoa (bri <sup>6</sup> zo'a—moss animals) includes <sup>a</sup> gro... | {
"Header 1": "MOLLUSCOIDA, TROCHELMINTHES, AND CHAETOGNATHA",
"Header 2": "MOLLUSCOIDA",
"token_count": 254,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Bugula is a common marine genus, the individuals of which are associated in a treelike colony that lives attached to some object in the water. These individuals are called zooids of which the soft parts are known as polypide. They are within the primitive coelomic cavity, the wall of which is the zooecium. The presence... | {
"Header 1": "MOLLUSCOIDA, TROCHELMINTHES, AND CHAETOGNATHA",
"Header 2": "Bugula",
"token_count": 2052,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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Under this layer is the mesodermal tissue which includes mesenchymatous cells and muscle fibers.
This group of animals is bisexual, and dimorphism (striking differences in form of the two sexes) is present. The males are usually much smaller and may even live as a parasite on the female. The males lack a well-develop... | {
"Header 1": "MOLLUSCOIDA, TROCHELMINTHES, AND CHAETOGNATHA",
"Header 2": "Bugula",
"token_count": 862,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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(By J. Teague Self, University of Oklahoma)
The Phylum Annelida (a nel'i da, form of a little ring) comprises an extremely large group of worms characterized by (1) the pres ence of a coelom surrounded by two layers of muscle, (2) metameres or segments, (3) a ventrally located segmental nervous system, (4) segmented,... | {
"Header 1": "PHYLUM ANNELIDA",
"token_count": 2031,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The fertilized egg develops into a trochophore larva, which metamorphoses into the adult animal.
In the central nervous system there are two suprapharyngeal ganglia dorsal to the pharynx. These are connected by means of commissures to the suhpharyngeal ganglion ventral to the pharynx. A nerve chain, composed of segme... | {
"Header 1": "PHYLUM ANNELIDA",
"token_count": 238,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
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The body of Lumbricus terrestris varies from six to fourteen inches in length and gives the appearance of a number of rings joined in a linear arrangement. The rings are the body segments, or metameres, and vary in number up to 175. In the adult the number of segments from the anterior end to the posterior end of the c... | {
"Header 1": "EARTHWORM",
"token_count": 587,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The body of the earthworm, if cut open along the mid-dorsal line, gives the general appearance of a tube within a tube, the digestive tube being the inner one and the body wall the outer one. The space between them is the coelom. The constricted regions dividing the segments on the outside correspond to the positions o... | {
"Header 1": "EARTHWORM",
"Header 2": "Internal Anatomy",
"token_count": 1383,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The blood of the earthworm consists of a clear liquid plasma in which there are numerous colorless cells. The red color of the blood, as seen in a living specimen, is due to a pigment known as Jiemoglohin suspended in the plasma and not in the corpuscles as is the case in many animals. A complicated system of blood ves... | {
"Header 1": "EARTHWORM",
"Header 2": "Circulatory System",
"token_count": 2032,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Earthworms have been used extensively in regeneration experiments because they possess the ability to regenerate lost parts. It has been demonstrated that when the anterior end is cut off, in front of the eighteenth segment, the segments from one to five will be regenerated. If the cut is made posterior to segment eigh... | {
"Header 1": "EARTHWORM",
"Header 2": "Regeneration",
"token_count": 1669,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The Echinodermata (e ki no dur'ma ta—hedgehog skin) constitute a rather backward phylum of animals which are thought to have undergone a certain amount of retrogression in structural features. That is, they seem to have a lower level of organization than that possessed by some of their ancestors. The modern echinoderms... | {
"Header 1": "PHYLUM ECHINODERMATA",
"token_count": 2046,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The row^s of tube feet serve as structures of
Fig. 120.—Diagram showing the internal anatomy of <sup>a</sup> sea cucumber. (From Wolcott, Animal Biology, published by McGraw-Hill Book Company.)
locomotion and for clinging. Some of them, next to the mouth, assist the tentacles in proc... | {
"Header 1": "PHYLUM ECHINODERMATA",
"token_count": 833,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
#### Habitat and Behavior
The starfish lives along the shores and in the shore waters (to a depth of over 125 feet) of our stony coasts of the Atlantic and Pacific, with scattered ones occurring in the Gulf of Mexico. A few scattered individuals may be found on muddy or sandy shores, but they are quite scarce. They a... | {
"Header 1": "PHYLUM ECHINODERMATA",
"Header 2": "STARFISH OF CLASS ASTEROmEA",
"token_count": 668,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The body wall is relatively strong and hard without being perfectly rigid. This condition is due to the presence of the calcareous skeletal plates throughout, which are bound together by connective tissue and muscular fibers. These plates are often called ossicles. They lie in a flat position in the aboral portions of ... | {
"Header 1": "PHYLUM ECHINODERMATA",
"Header 2": "Internal Anatomy",
"token_count": 2035,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
In addition to this the coelomic fluid, which occupies the coelom and bathes all of the organs, serves as a circulatory medium in that it absorbs the digested food and distributes it. This fluid bears amoebocytes which are cells capable of picking up particles of waste material and carrying them to the dermal branchiae... | {
"Header 1": "PHYLUM ECHINODERMATA",
"Header 2": "Internal Anatomy",
"token_count": 1472,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The phylum Mollusca includes such familiar animals as the snails, clams, oysters, and cuttlefish. Even though they appear different externally, all are soft-bodied, unsegmented, usually bilaterally symmetrical, and most of them produce a shell composed principally^ of calcium carbonate. A muscular foot is present which... | {
"Header 1": "PHYLUM MOLLUSCA",
"Header 2": "GENERAL CHARACTERS",
"token_count": 2049,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
the gliding movements are scarcely perceptible. In some marine snails the surface of the foot is covered with cilia, the latter facilitating movement. The visceral hump, which encloses the digestive, circulatory, respiratory, excretory, and reproductive systems, is protected by the shell which is lined with the mantl... | {
"Header 1": "PHYLUM MOLLUSCA",
"Header 2": "GENERAL CHARACTERS",
"token_count": 2044,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
#### External Features
**Shell.**—Unlike the snail whose shell is of one piece, the clam shell is composed of two parts called valves (hence, *bivalves*) which are attached together at the dorsal surface by a hingelike ligament.
Fig. 141.—External (A) and internal (B) shell feature... | {
"Header 1": "PHYLUM MOLLUSCA",
"Header 2": "GENERAL CHARACTERS",
"token_count": 2039,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Classification of this phylum is based on the nature of the foot, and respiratory organs; shape and structure of the shell; arrangement and structure of the nervous and reproductive systems.
#### Class I. Amphineura
Includes the Chitons, which are found abundantly on rocks between tide marks along the Atlantic and ... | {
"Header 1": "PHYLUM MOLLUSCA",
"Header 2": "CLASSIFICATION",
"token_count": 471,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Fig. 146.—Representatives of three classes of mollusks. Class Amphineura, Ischnochiton; Class Scaphopoda, Dentalium; Class Cephalopoda, Loligo brevipennis (squid) and Polypus bimaculatus (octopus).
#### Class III. Gastropoda
Includes the snails and slugs. Approximately fifty-five thousand species have been discover... | {
"Header 1": "Loligo brevipennis Polypus bimaculatus (Octopus)",
"token_count": 1724,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Arthropoda (ar throp'O da, joint foot) is the name of the largest known group of animals. As the name implies, all representatives of the phylum have paired, jointed appendages and <sup>a</sup> definite tendency toward specialization of them. Their bodies are triploblastic, segmented, bilateral, and covered by a chitin... | {
"Header 1": "PHYLUM ARTHROPODA",
"token_count": 1510,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
For the most part crayfishes (crawfishes, crawclads, fresh-water lobsters) are inhabitants of fresh-water streams and ponds where there is sufficient calcium carbonate in solution for purposes of skeleton formation. These animals may be found moving about on the bottom, or they may be in hiding under some stone or log,... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Habitat and Behavior",
"token_count": 2026,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
#### Internal Structure
Beneath the shell-like, chitinous exoskeleton there is a very rep resentative set of systems. As in most higher animals the segmentation is retained in the muscular system, nervous system, and to <sup>a</sup> degree in the circulatory system. Earlier in the chapter it was pointed out that th... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Habitat and Behavior",
"token_count": 2043,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
When the crayfish molts, the statocysts are temporarily lost and new ones form as the new skeleton develops. If there are no solid objects in the water in which a crayfish lives during molting, there will be no statoliths in the statocysts and the ajiimal has an impaired sense of equilibrium. Experimenters have placed ... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Habitat and Behavior",
"token_count": 1031,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
These animals are dioecious (sexes separate) and the mating takes place either in the spring or fall or perhaps both. The spring hatch become well developed before winter. The eggs produced in the fall may not be laid before spring.
Fig. 158.—Development of the crayfish. A, Young crayf... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Reproduction",
"token_count": 1028,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Crayfish and the entire class Crustacea are of considerable importance to man. The crayfish, lobster, crab, shrimp, and others are used directly as food to the extent that it is an industry valued at several million dollars annually in the United States. The numerous smaller genera, like Daphnia, Cyclops, Cypris, Gamma... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Economic Relations",
"token_count": 247,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Besides crayfish the order Decapoda includes lobster, shrimp, and crab. They all have ten walking legs for which they are named. The crayfish and lobster are verj^ similar except in size. The shrimps and prawns are marine and resemble the crayfish except that they do not have the great pinchers (chela) and the abdomen ... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Characterization of Other Crustacea",
"token_count": 1458,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
A statement of this idea, which was developed by von Baer, Haeckel, and others, and is so well illustrated by the comparison of the phylogenic and embryonic stages of certain Crustacea, may well come at this point. This theory maintains that certain developmental stages or structures of the individual are related to an... | {
"Header 1": "PHYLUM ARTHROPODA",
"Header 2": "Recapitulation Theory",
"token_count": 527,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
(By Vasco M. Tanner, Brigham Young University)
#### Onychophora
An interesting group of arthropods, now considered as the class Onychophora, is restricted to the more tropical and semitropical regions of the earth south of the Tropic of Cancer. These primitive nocturnal forms, according to Austin H. Clark, are foun... | {
"Header 1": "PHYLUM ARTHPtOPODA (CONT'D)",
"Header 2": "ONYCHOPHORA AND MYRIAPODA",
"token_count": 2022,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
(By Vasco M. Tanner, Brigham Young University)
Probably the most heterogeneous class of arthropods is the class Arachnida, which is now a pigeon-hole for the spiders, scorpions, mites, ticks, pseudoscorpions, harvestmen, whip scorpions, bear animalcules, king crabs, and several other less common orders, such as the P... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "ARACHNIDA",
"token_count": 1427,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
For purposes of this chapter we shall confine our discussion to but five of the common orders of the class Arachnida : (1) Araneida, the true spiders; (2) Acarina, the mites and ticks; (3) Scorpionida, the scorpions; (4) Phalangida, the daddy longlegs; and (5) Xiphosura, the king crabs.
According to <sup>a</sup> rece... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "Classification of the Arachnida",
"token_count": 2049,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Another interesting little group of arachnids is the order Solpugida, found in the same territory as the scorpions and represented by twelve species contained in three genera. Eight of the species be long in the genus Eremohates.
The Phalangida, commonly called harvestmen and daddy longlegs, can be distinguished fr... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "Classification of the Arachnida",
"token_count": 425,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
(By Vasco M. Tanner, Brigham Young University)
Insects are the most abundant creatures on the earth today. There is said to be over 650,000 living species, many of which have never been seen by the great majority of mankind. This, no doubt, is because insects exist in every type of habitat known. They are found in se... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "CLASS INSECTA",
"token_count": 2043,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The labium is hinged to the head by the mentum from which extends one or two pairs of lobes, the ligula. Projecting from the mentum on each side is a palpus which consists of one to four segments ; it functions as a sen soiy organ, probably detecting senses similar to our own senses of taste and smell.
The hypopharyn... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "CLASS INSECTA",
"token_count": 2031,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
A, Red-legged locust, Melanoplus femur-rubrum DeGeer, male; B, Haldeman's locust, Hippiscus corallipes Hald.; C, Shoshone grasshopper, Schistocerca shoshone Thomas, female; D, two striped Mermiria, Mermiria bivittata Serville; E, western meadow grasshopper, Conocephalus vicinus Morse, female. (From Henderson, Utah Agri... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "CLASS INSECTA",
"token_count": 2042,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The family Coreidae is represented by the squash bug, Anasa tristis (DeG.) ; and the family Corizidae by the box-elder bug, Leptocoris trivittatus (Say). The false chinch bug, Nysius ericae (Schilling), is a common species of the family Lygaeidae. The lace bug, CorytJiucha distincta Osborn and Drake is a handsome Tingi... | {
"Header 1": "PHYLUM ARTHROPODA (CONT'D)",
"Header 2": "CLASS INSECTA",
"token_count": 1199,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Order Odonata.—The dragonflies and damsel flies are insects with large compound eyes, mandibulate mouth parts, four membranous wings that are finely veined, and a long slender abdomen. The naiads are aquatic and possess a labium which has been highly modified. It can be greatly extended for the catching and holding of ... | {
"Header 1": "Hemimetabolous Insects With Incomplete Metamorphosis",
"token_count": 2005,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
(From Sorensen and Knowlton, permission Utah Agricultural Experiment Station.)
The following are some examples of common species: the monarch butterfly, *Danaüs menippe* (Hubner), is widely distributed through the United States, parts of Canada, and south into the tropics. This species is typical of the family Danaïd... | {
"Header 1": "Hemimetabolous Insects With Incomplete Metamorphosis",
"token_count": 1589,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Other orders than the ones discussed above are included in the notable treatises on entomology. These are in the main, however, rare and little known insects. Professor Comstock in his An Intro duction to Entomology, recognizes twenty-five orders : the Zoraptera, insects resembling termites in many respects, and consis... | {
"Header 1": "Hemimetabolous Insects With Incomplete Metamorphosis",
"Header 2": "Other Orders",
"token_count": 2032,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The above condition applies primarily to two-celled nests, although it might be equally true of the three-celled types.
"It is evident from this study that the eggs laid in July and August hatch and remain in a late larval instar throughout the winter. On August <sup>2</sup> <sup>a</sup> number of larvae were collect... | {
"Header 1": "Hemimetabolous Insects With Incomplete Metamorphosis",
"Header 2": "Other Orders",
"token_count": 1522,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
V
Insects attack all kinds of growing crops and plants. The destruction of plants and their products valuable to man amounts to over a billion dollars annually. This great loss goes on because of the unabated and persistent struggle of the insects to maintain their "place in the sun." Plants are not only eaten and da... | {
"Header 1": "Hemimetabolous Insects With Incomplete Metamorphosis",
"Header 2": "ECONOMIC RELATIONS",
"token_count": 811,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The locust or grasshopper is one of the most common insects, being known to practically all people, because very few boys and girls grow up without having some experience with a grasshopper. They are widely distributed throughout the world, living on grass and low-growing plants of the fields and open country. In the U... | {
"Header 1": "REPRESENTATIVE INSECTS",
"Header 2": "THE LOCUST",
"token_count": 2045,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The segments bear a series of pads, which terminate on the last one in a large suckerlike disc known as the pulvillus.
There are two pairs of wings. The first pair or wing covers, also called tegmina, is attached to the dorsal region of the mesothorax. They are leathery in texture and do not fold fanlike over the abd... | {
"Header 1": "REPRESENTATIVE INSECTS",
"Header 2": "THE LOCUST",
"token_count": 2049,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The legs and wings are coordinated in their movements by the thoracic ganglia. In the vertebrates the
nervous system is dorsal to the digestive tract, and the foreshadowing of this evolutionary change is initiated in the insects by the development in the cephalic region (Figs. 203 and 204).
The grasshopper is dioec... | {
"Header 1": "REPRESENTATIVE INSECTS",
"Header 2": "THE LOCUST",
"token_count": 446,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The June bugs or May beetles are members of the family Scarabaeidae, a very large and important family of beetles. More than one hundred and twenty-five species of these beetles have been reported as occurring in the United States and Canada, the majority of them being considered as pests. The larvae or white grubs liv... | {
"Header 1": "REPRESENTATIVE INSECTS",
"Header 2": "THE JUNE BUG",
"token_count": 1054,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The honey bee belongs to the order Hymenoptera, composed of insects with two pair of membranous wings, well-developed biting or sucking mouth parts, and the females usually with a stinging organ. Many of the Hymenoptera, such as the honey bee, live <sup>a</sup> social life, developing colonies consisting of three types... | {
"Header 1": "REPRESENTATIVE INSECTS",
"Header 2": "THE HONEY BEE",
"token_count": 1129,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Phylum Chordata (kor da' ta, cord) is made up of the group of animals which includes man himself and in general the more conspicuous, better known animals.
#### Characteristics
There is a rather wide range of variation as to form and size in the group. It includes minute sessile forms, small colonial forms, mud-bur... | {
"Header 1": "PHYLUM CHORDATA",
"token_count": 635,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
There are approximately 40,000 different species in this phylum which is divided into four established subphyla as follows:
Hemichorda (hemikor'da, half cord) or sometimes known as Enteropneusta (en ter op nus'ta) includes order Balanoglossida with its four families, ten genera and twenty-eight species, and order Cep... | {
"Header 1": "PHYLUM CHORDATA",
"Header 2": "Classification",
"token_count": 400,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
One of the species of Balanoglossus or Dolichoglossus koivalevskii will serve as an example. They are wormlike animals which burrow into the mud and sand along the seashore. They range from <sup>6</sup> to 10 inches in length. Others of the subphylum may be as short as one inch or still others as long as four feet. The... | {
"Header 1": "PHYLUM CHORDATA",
"Header 2": "SUBPHYLUM HEMICHORDATA",
"token_count": 1081,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Subphylum Urocliorda includes <sup>a</sup> number of common representative marine forms, such as Salpa, Cynthia, Ciona, Clavelma, Ascidia, and Molgula. The latter genus represented by M. manhattensis will be given particular consideration here. This animal is com monly known as sea lemon, sea peach, or sea squirt. The ... | {
"Header 1": "SUBPHYLUM UROCHORDA, MOLGULA",
"token_count": 1508,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
There are usually listed twenty-eight species in this group which are rather locally distributed over the world. There are four species on American shores : Bra7ichiostoma virginiae, B. floridae, B. lermudae, and B. californiense. Amphioxus or the lancelet, Branchiostoma lanceolatus, the European form, is an admirable ... | {
"Header 1": "SUBPHYLUM UROCHORDA, MOLGULA",
"Header 2": "SUBPHYLUM CEPHALOCHORDA, AMPHIOXUS",
"token_count": 2037,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
In this group to which man himself belongs are found the dis tinctive chordate characteristics at some time in the life of the indi vidual. In terrestrial forms there are certain modifications to produce other structures. Metamerism and bilateral symmetry are universal characteristics among vertebrates. The segmented v... | {
"Header 1": "THE VERTEBRATE ANIMAL: SUBPHYLUM VERTEBRATA",
"token_count": 2007,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
The presence of <sup>a</sup> cuticle in some and the secretion of <sup>a</sup> hard shell in others seem to be the particular developments related to these special functions in this group. Arcella, Difflugia, the Foraminifera, and Radiolaria exemplify this adaptation.
The skeleton and integumentary structures serve t... | {
"Header 1": "THE VERTEBRATE ANIMAL: SUBPHYLUM VERTEBRATA",
"token_count": 2025,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Diastases or diastatic enzymes—split carbohydrates
- (a) Ptyalin in saliva
- (b) Amylase in pancreatic juice
- (c) Glycogenases—liver and muscles Converts glycogen to glucose
- 2. Lipase or lipolytic enzyme—splits fats
- (a) Steapsin in pancreatic juice
- 3. Inverting enzymes—convert disaccharids to the less complex mo... | {
"Header 1": "THE VERTEBRATE ANIMAL: SUBPHYLUM VERTEBRATA",
"token_count": 2023,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
Normally there is a constant supply of dextrose (0.1 to 0.15 per cent) in the blood and this level must be maintained. The final oxidation products of carbohydrates in the body are heat, kinetic energy, water, and carbon dioxide. The last two are dis charged from the body as waste products. Fat is converted to dextrose... | {
"Header 1": "THE VERTEBRATE ANIMAL: SUBPHYLUM VERTEBRATA",
"token_count": 1014,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
- (a) Sources: Green leaves, alfalfa, also certain bacteria of the "intesti nal flora."
- (b) Functions: Influences the production of prothrombin by the liver (prothrombin is necessary for blood clotting).
- (c) Effects of deficiency: Blood fails to clot.
The Respiratory System.—The respiratory system is at least in ... | {
"Header 1": "VI. Vitamin K (C3,H4e02) —antihemorrhagic.",
"token_count": 2022,
"source_pdf": "datasets/websources/biochem/textbookofzoolog00pott.pdf"
} |
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