FUNCTIONAL VARIATION IOI 



Females deprived of their ovaries develop to some extent the 

 characters of the male. Spayed heifers are not at all like bulls, 

 but they do resemble steers. Unsexing animals seems, therefore, 

 to induce a kind of mediocre development, although it gives rise 

 to four distinct types instead of two for each species. 



Many females in later life assume certain characters of the 

 male. Cows bellow and paw dirt like bulls ; hens grow spurs 

 and try to crow ; women sometimes grow a straggling beard and 

 acquire a heavy voice. These changes do not by any means 

 appear in all cases, but when they do appear they may be regarded 

 as symptoms of loss of the sexual function and of cessation of 

 breeding powers. 1 



This influence over the functions of the body by organs 

 apparently having no connection with the parts affected is akin 

 only to that of certain glands like the thyroid, whose function is 

 entirely unknown, but in whose absence children -grow up defect- 

 ive both physically and mentally. 2 We are at this point very 

 near to the forces that determine the activities of living matter, 

 but the mysteries involved are in no sense cleared up ; they 

 rather deepen instead as they are studied. It is as if our vision 

 were obstructed, not by a curtain that can be drawn aside afford- 

 ing a view beyond, but rather by a solid wall fixing the limits not 

 only of vision but of progress as well. 



Functional variation due to the modifying influence of the 

 conditions of life. The conditions of life are most active in stim- 

 ulating or depressing normal activities, but they are not without 

 effect upon their character as well. Plants having a fixed abode 

 are more dependent upon their environment and therefore less 

 resistant than animals, though species living in confined waters 

 are little better off than plants in this regard. 



1 Though bearing but indirectly upon the present question, it is worthy of 

 remark at this juncture that many individuals of each sex seem to be naturally 

 endowed with more than the usual proportion of the characters of the opposite 

 sex and to be correspondingly short in those of their own. Thus we have our 

 " mannish " women and our " effeminate " men, distinguished not only for their 

 tastes and their mental characteristics generally but for their body conformation as 

 well. These abnormal unions of male and female traits are often strange mixtures 

 indeed, and may well be avoided in the breeding yard. 



2 Loeb, Physiology of the Brain, p. 207. 



