THE senior author of this book is well known in zoological circles for his two-volume work on “Experimental Morphology” —one of the most novel and ambitious of modern text-books; and his wife, whose aid he acknowledged in its preface, now appears, as joint author of the present equally ambitious production, which has for its object nothing short of a revolution of the methods of zoological teaching in vogue in the secondary schools of the United States. The key to the plan of the work and nature of its contents lies in the prefatory pronouncement that the “vast majority of secondary students are not to be zoologists, but rather men of affairs,” and that “what the ordinary citizen needs” zoologically is (not a course in comparative anatomy but) “an acquaintance with the commonest animals” —a knowledge of “where else over the world the common animals of his State are to be found, and of foow animals affect man,” and that to know these matters is for him “more important than to know the location of the pedal ganglion of the snail.” There can be little doubt that in this resolve the authors are in agreement with a large section of active teachers, but it must not be forgotten that the didactic system of laboratory instruction in vogue, against which they are in the long run entering a protest, has in its development become modified beyond the Conceptions and intentions of its founders, and that as originally planned it did not ignore non-anatomical considerations to the extent their attitude implies. In their forcible recognition of the later tendency towards so doing, however, and. their bold attempt to overcome it, they have performed a useful task, but experience can alone decide upon the wisdom of the remedy they propose.