Page:Popular Science Monthly Volume 16.djvu/825

 other living things, that the reader is supposed to enter upon the consideration of the facts which Professor Huxley lays before him.

No pains have been spared in the illustration of the text—the woodcuts (eighty-one in number) reflecting great credit both on the artist for his skill and on the publisher for his enterprise. We have, after a general disquisition on the natural history of the crayfish (by



no means the least interesting in the book), two devoted to the consideration of the crayfish as a mechanism—in fact, its physiology. Here a good deal of the anatomy is given and considered from the point of view involved in the question, "What does it do?" Then we have the morphology of the English crayfish—the structure and development of the individual minutely set forth, even each joint of each leg, and each tuft on each gill, and each group of hairs, being described and figured. We are enabled by the courtesy of the