SCIENCE 



Editorial Committbb : S. Newcomb, Mathematics ; E. S. Woodwaed, Mechanics ; E. C. Pickkeing, 



Astronomy; T. C. Mkndenhall, Physics; E. H. Thueston, Engineering; Iea Ekmsen, Chemistry; 



J. Lb Conte, Geology; W. M. Davis, Physiography; O. C. Maesh, Paleontology; W. K. Beooks, 



C. Haet Mkeeiam, Zoology; S. H. Scuddee, Entomology; C. E. Bessey, N. L. Beitton, 



Botany; Heney F. Osboen, General Biology; C. S. Minot, Embryology, Histology; 



H. P. BowDlTCH, Physiology; J. S. Billings, Hygiene ; J. McKeen Cattell, 



Psychology; Daniel G. Beinton, J. W. Powell, Anthropology. 



Friday, June 17, 1898. 



CONTENTS: 

 Tlie Vital Equilibrium and the Nervous System : 



Peesidbnt C. L. Heeeick 813 



iS'ome Experiments on Animal Intelligence: Ed- 



WAED THOENDIKE 818 



The American Society of 3Iechanical Engineers : 

 Peofessob E. H. Thueston 824 



Botanical Notes : — 



Botany and Agriculture ; Papers on tJte Diseases 

 of Plants: Peofessoe Chaeles E. Bessey. ..842 



Owrrent Notes on Anthropology : — 



The Aryan Question ; Polyandry among the Sem- 

 ites ; Tlie ' Folk^mind :' Peofbssoe D. G. Bein- 

 TON 826 



Notes on Inorganic Chemistry: J. L. H 827 



Scientific Notes and News : — • 



Vasco da Qama Celebration; General 827 



University and Educational News 831 



Discussion and Correspondence : — 



Color Vision: PROFESSOR E. B. Titchenee. 

 A Precise Criterion of SiJecies : Dr. Geeeit S. 

 Millee, Jr 832 



Scientific Literature : — 



Packard's Text-book of Entomology : Peofessoe 

 William Moeton Wheelee. Pasteur : Peo- 

 fessoe Edwin O. Joedan. Stratton and Milli- 

 kan's Course of Laboratory Experiments in General 

 Physics: Professor W. Le Conte Stevens... 834 



Scientific Journals 839 



Societies and Academies : — 



Philosophical Society of Washington: E. D. 

 Peeston. Academy of Natural Sciences of 

 Philadelphia: Edw. J. Nolan 839 



New Books 840 



MSS. intended for publication and books, etc., intended 

 for review should be sent to the responsible editor. Profes- 

 sor J. McKeen Cattell, Garrison-on-Hudson, N. Y. 



TBE VITAL EQUILIBRIUM AND TMENEBVOUS 



8YSTE3I. 



It is noticeable that there has been a ten- 

 dency on the part of our most thoughtful 

 working biologists, especially such as are 

 equally equipped for the philosophical and 

 biological aspects of cellular biology, to seek 

 some avenue of return to the vitalistic point 

 of view. It has become sufficiently plain 

 that the most conspicuous triumphs of his- 

 tology, even in the domain of cytology, have 

 rather reduced than increased the prob- 

 ability of securing an explanation of vital 

 phenomena and specific heredity and in- 

 tegrity from the study of structure alone. 

 A strong tendency is visible toward a 

 dynamic point of view. "We believe that a 

 consistant application of a dynamic hypoth- 

 esis is destined to prepare the way for 

 greater advances, not only in interpretation, 

 but also in practical applications of biolog- 

 ical principles. When we come to regard 

 the visible structural data of histology as 

 expressions of dynamic processes rather 

 than the causes of these processes, and 

 when we have agreed to apply other criteria 

 than that offered by materialism to the 

 phenomena of heredity, we may be able to 

 shake ourselves free of preconceptions that 

 have done much to retard the normal de- 

 velopment of both biology and psychology. 

 It is true that a strong prejudice exists 

 against the dynamic method because of the 

 belief that it tends to limit research and 



