Title: Biology and man
Identifier: biologyman00grue (find matches)
Year: 1944 (1940s)
Authors: Gruenberg, Benjamin C. (Benjamin Charles), 1875-1965; Bingham, N. Eldred (Nelson Eldred), 1901-
Subjects: Biology; Human beings
Publisher: Boston, New York, (etc. ) Ginn and company
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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Lawrence H. Kobblns A FOOD CHAIN Beginning with the simplest chlorophyl-bearing plants, each organism eats, and in turn is eaten. Animals generally get their food from those that are smaller. Each takes what he can and gives only what he must vantages over larger animals. Wolves will attack a herd of cattle or deer. The driver ants, which always travel in vast regiments, will attack large animals—lizards, snakes, and even cattle. If the latter cannot escape the swarm by running away, the countless ants will sting it to death and carry off the flesh bit by bit. Not all flesh-eaters, however, are compact and ener- getic fighters. The whale, for example, takes into its mouth a fraction of the ocean, filters out most of the water, and finally swallows some hundred pounds of small fry. As we should expect, a species that serves as food must be more numerous than another which feeds upon it. It is estimated, for example, that one Hon may kill as many as forty or fifty zebras in the course of a year. Since many zebras must die every year without waiting for lions to kill them, the ratio of zebras to lions must be much greater if zebras are to survive—or, for that matter, if the lions are to survive. For if lions destroy too much of their food supply, it will go hard with them the following season. To be sure, lions can feed on other animals besides zebras; but the principle is still the same. The food chain is in a sense endless. Or rather, it goes round and round, as we saw in considering food cycles. A single shrub may have on it millions of plant lice. These plant lice furnish food for thousands of insects and spiders. 56\

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