M. 



N3/ 



COLUMBIA UNIVERSITY BIOLOGICAL SERIES. V. 



THE 



FOUNDATIONS OF ZOOLOGY 



BY 



WILLIAM KEITH BROOKS, Ph.D., LL.D. 



PROFESSOR OF ZOOLOGY IN THE JOHNS HOPKINS UNIVERSITY 



PUBLISHED FOR THE COLUMBIA UNIVERSITY PRESS BY 



THE MACMILLAN COMPANY 



LONDON : MACMILLAN & CO., LTD. 



All rights reserved 



