CXL ADMINISTRATIVE REPORT [eth. ann. 20 



It may be well to reexamine briefly the nature of activital 

 movement, altliouiih the subject has more ehiborate treatment 

 in my former work entitled Truth and Error. Movements in 

 the animal body" are performed by nmsclejs. The muscles are 

 found in opposing- jiairs, or more or less in opposing groups, 

 which have the function of contracting and relaxing, and one 

 may contrai't while the other relaxes, and thus originate a 

 movement in the animal body. The contraction nnd relaxa- 

 tion are produced through the agency of metabolism. When 

 metabolism is constructive it is called anabolism, when it is 

 destructive it is called catabolism. I suppose that catabolism 

 produces contraction and that anabolism produces relaxation, 

 but of this I am not sure Certain it is that when nmscles are 

 contracted iuid relaxed, metabolism in l)oth its methods is 

 involved, so that all muscular nction is founded on metabolic 

 action, and metabolic action involves afifinitv, which is choice, 

 as we have lieretofore deductively demonstrated. The move- 

 ments in animals which depend on muscular action due to the 

 function of o})posing muscles, one of which relaxes and the 

 other contracts, we call activity. Activity is under tlie control 

 of the will, for the individual animal controls activity indi- 

 rectly by controlling the metabolism of molecules. It is thus 

 that activity is innate in every living animal body. 



Emotional Language 



The natural expression of strong emotion is cultivated by 

 man in the earlier .stages of .society and likewi.se in childhood, 

 so that an artiticial language of the emotions is j)roduced. 

 Thus we have in laughter the language of jo^:. and in weeping 

 the language of grief, each highly expressive of emotion. 



To man who already uses lang'uage in its liighh' developed 

 state, it may seem at first blush that laughter is a ])urely nat- 

 ural ebullition of joN', but on further examination he will see 

 that it is no less artificial and conventional than the term joy 

 itself; yet it is probabh- universal with mankind and is an 

 expression iidierited from his anthrojioid ancestor. Tliose 

 species nearest allied to this anthro])0]iithecus indulge in 

 laughter, and even scpiii-rels chatter in a uiaimer exceedingly 

 suii'o-estive of laui^lUer. 



