Scientific Proceedings. 



3 



the effects of peripheral coordination based on joint and muscle 

 mechanics has been ascertained. These statements are the result 

 of two years of careful study of the effect of mechanical conditions 

 on the action of the separate muscles of the hind leg of the frog, 

 when these muscles have been electrically excited to action, in 

 different positions of the bones. 



4 (147) 



The senses and intelligence of the Chinese dancing mouse. 

 By ROBERT M, YERKES. 



[From the Psychological Laboratory of Harvard University^ 



For a few days during the first month of post-natal life the 

 dancing mice which I have studied respond definitely to sounds, 

 but neither direct nor indirect methods of testing auditory sensi- 

 tiveness furnish any evidence of it in the adult. 



Brightness vision is fairly acute ; color vision is poorly devel- 

 oped. I have some evidence of the discrimination of red and blue, 

 and of red and green, but no evidence that blue and green can be 

 distinguished. In visual discrimination the mice apparently depend 

 upon brightness differences. 



The behavior of the dancing mouse is readily modifiable. 

 Choice, by exclusion, of one of two objects which differ in bright- 

 ness, with electrical stimulation in the case of a wrong choice, indi- 

 cates that from 40 to 100 repetitions of an experience is necessary 

 for the formation of a perfect habit. Such a modification of 

 behavior lasts for from two to five weeks. 



Modifications of behavior occur more rapidly in the male than 

 in the female. Individual differences in plasticity and in the per- 

 manency of modification are marked. 



There is little evidence of any form of imitative tendency in 

 behavior. 



5 (148) 



On the motor activities of the alimentary canal after 

 splanchnic and vagus section. 



By W. B. CANNON. 



[From the Laboratory of Physiology in the Harvard Medical School ^\ 

 In this investigation one series of animals was studied with only 



