Animal Life: A First Book of ZoölogyD. Appleton, 1900 - Всего страниц: 329 |
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Стр. ix
... tion of instincts , 243. - Feeding , 244. - Self - defense , 245. - Play , 247. - Climate , 248. - Environment , 248. - Courtship , 248. - Repro- duction , 249. - Care of the young , 250. — Variability of instincts , 251. - Reason , 251 ...
... tion of instincts , 243. - Feeding , 244. - Self - defense , 245. - Play , 247. - Climate , 248. - Environment , 248. - Courtship , 248. - Repro- duction , 249. - Care of the young , 250. — Variability of instincts , 251. - Reason , 251 ...
Стр. 4
... tion of the protoplasm . " * * The physical structure of protoplasm has been much studied , but even with the improved microscopes and other instruments neces- sary for the study of minute structure , naturalists are still very far from ...
... tion of the protoplasm . " * * The physical structure of protoplasm has been much studied , but even with the improved microscopes and other instruments neces- sary for the study of minute structure , naturalists are still very far from ...
Стр. 6
... tion - the Amaba moves . There are no muscles in this tiny body ; muscles are composed of many contractile cells massed together , and the Amoeba is but one cell . But it is a contractile cell ; it can do what the muscles of the com ...
... tion - the Amaba moves . There are no muscles in this tiny body ; muscles are composed of many contractile cells massed together , and the Amoeba is but one cell . But it is a contractile cell ; it can do what the muscles of the com ...
Стр. 8
... tion in its simplest degree . If food is abundant the Amaba soon increases in size . The bulk of its body is bound to increase if new substance FIG . 4. - Amoeba polypodia in six successive stages of division . The dark , white ...
... tion in its simplest degree . If food is abundant the Amaba soon increases in size . The bulk of its body is bound to increase if new substance FIG . 4. - Amoeba polypodia in six successive stages of division . The dark , white ...
Стр. 27
... tion . But the process of mul- C GOEBEL ) . Three stages in the conjugation and formation of the resting spore . A , two cells just fused ; B , the two cells completely fused , but with flagella still per- sisting ; C , the resting ...
... tion . But the process of mul- C GOEBEL ) . Three stages in the conjugation and formation of the resting spore . A , two cells just fused ; B , the two cells completely fused , but with flagella still per- sisting ; C , the resting ...
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adaptation adult alimentary canal Amaba ants artificial selection becomes bees beetles birds body wall breathing butterfly called cavity chitin CLASS colony color complex animals composed conjugation crab differentiation digestion divide division of labor ectoderm egg cells embryo existence feed female fertilized fish flagella free-swimming function gastrula Globigerinæ habits hatched higher animals honey-bee Hydra inclosed increase insects instinct intestine jelly-fishes kinds of animals larva larvæ layer live male mals mammals many-celled animals mass medusæ metamorphosis naturalists nerve nest nucleus ocean one-celled organs outer oxygen Pandorina papillæ Paramecium parasites parent perform plant-lice plants polyp prey primitive processes produced protoplasm Protozoa pseudopods pupa queen Radiolaria reproductive cells Sacculina sea-anemone shell simple simplest animals single cell special sense species sperm cells spherical sponge stage structure substance surface swimming tentacles tion tissues vertebrates Volvox Vorticella wings workers worms young
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Стр. 115 - There is no exception to the rule that every organic being naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair. Even slow-breeding man has doubled in twenty-five years, and at this rate, in less than a thousand years, there would literally not be standing room for his progeny.
Стр. 215 - He cannot be mistaken for any other, and his flaming vest and blue stockings show that he does not court concealment. He is very abundant in the damp woods, and I was convinced he was uneatable so soon as I made his acquaintance and saw the happy sense of security with which he hopped about. I took a few specimens home with me, and tried my fowls and ducks with them ; but none would touch them. At last, by throwing down pieces of meat, for which there was a great competition amongst them, I managed...
Стр. 20 - ... inhabitants of the water has followed a roundabout path from the surface to the bottom and then back into the water. When this fact is seen in all its bearings and its full significance is grasped, it is certainly one of the most notable and instructive features of evolution. The food-supply of marine animals consists of a few species of microscopic organisms which are inexhaustible and the only source of food for all the inhabitants of the ocean.
Стр. 116 - The elephant is reckoned the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase; it will be safest to assume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old ; if this be so, after a period of from 740 to 750 years there would be nearly nineteen million elephants alive, descended from the first pair.