PROFESSOR OF PHYSIOLOGY, PRINCETON UNIVERSITY
PHILADELPHIA AND LONDON J. B. LIPPINCOTT COMPANY
COPYRIGHT, 1920. BY J. B. LIPPINCOTT COMPANY
Electrotyped and Printed by J. B. Lippincott Company.
The Washington Square Press, Philadelphia, U. S. A.
EDITORS' ANNOUNCEMENT
The rapid increase of specialization makes it impossible for one author to cover satisfactorily the whole field of modern Biology. This situation, which exists in all the sciences, has induced English authors to issue series of monographs in Biochemistry, Physiology, and Physics. A number of American biologists have decided to provide the same opportunity for the study of Experimental Biology.