Page:Popular Science Monthly Volume 75.djvu/178



HE data of biology are living plants and animals. These are what nature presents. To these we must always go in order to make a beginning at any investigation. Is one interested in ganglionic cells, or germ cells, or liver secretions, or degenerate organs? He must find some kind of animal that has, or produces, or can yield such things. In making a successful quest for "material," it always turns out that a particular individual plant or animal, one or more, furnishes it. One may not be able to tell exactly what he means by an individual tree or man, but he must have one before he can study it or any part of it. Definitions of natural objects come at the end, rather than at the beginning, of our knowledge of them.

We biologists frequently speak of the principle of life, or the germs of life, and of many other particular manifestations of organisms, as though they were something really existent independently of particular organisms. Such questions as: Which came first, or is more fundamental, the chick or the egg; structure or function; life or organization? are frequently asked with more or less seriousness. Herbert Spencer devotes considerable space to the inquiry as to whether life or organization appeared first. He writes:

He continues:

If Life is shown by inner actions so adjusted as to balance outer actions