ANTHROPOLOGY. 



687 



* This index is reduced by the length of basis cranii. 



t The relative, not the actual, size of teeth makes them Megadont. 



Mr. Nathaniel Alcock has advanced a curious theory about the black- 

 ness of the tropical man. The gist of this theory is, that the pigment 

 of the negro skin offers an impediment to the undue excitation of the 

 nervous system by the actinic rays of light. 



Considerable interest has been excited by a physiological paper of 

 Dr. Clevenger upon the disadvantages of the upright position. Assum- 

 ing that man once progressed on all fours, it is shown that the valves 

 in the veins facilitated the return of blood to the heart. But in the up- 

 right position there are certain veins in which such return is rather im- 

 peded, producing hemorrhoids and other disorders. 



One of the most practical investigations now going on is that which 

 essays to bring into some relation measurement of the living and of 

 the skeleton. Dr. Paul Toi)iuard, while finding the most satisfactory 

 agreement between these two measures, has discovered that in some 

 respects, notably in the nasal index, the living subject gives better 

 ethnic results. 



PSYCHOLOGY. 



Comparative psychology has received an important addition in the ef- 

 forts of Sir John Lubbock to teach a dog to understand card language 

 and to communicate his wishes in the same manner. Dr. P. A. Chad- 

 bourne, of New York, has revived the study of what is called instinct in 

 animals, comparing it with the mental powers of man. The scrutiny of 



