MENTAL DIFFERENCE AND DISORDER. 205 



becomes sometimes even blind, when moulting; while, in 

 other birds, this physiological process produces enfeeblement 

 of memory (Houzeau). 



In so far as the female sex is exclusively liable to the 

 derangements both mental and physical that accompany 

 or characterise pregnancy, parturition, the puerperal state, 

 and lactation, it may be inferred, and naturally, that the sex 

 in question is necessarily more liable than the other to the 

 various forms of mental disorder. But this by no means fol- 

 lows ; for the male sex has its peculiar disadvantages, which 

 may or ma-y not counterbalance those of the female. As the 

 bread-winner, forager, protector of mate and young, as the 

 leader of flocks and herds, the male is much more exposed to 

 a variety of dangers, and is much more liable to that which 

 is more frequently a cause of mental disquiet and upset than 

 mere physical danger viz., to protracted anxieties, or wor- 

 ries. And it is just possible that these anxieties and risks, 

 his peculiar duties, with the results they may involve, may 

 counterbalance maternity and its antecedent or immediately 

 succeeding conditions, in which case we should expect to 

 find the sexes, on the whole, equally liable to the major and 

 minor forms of insanity. 



But in point of fact, the relative liability to insanity of 

 the sexes among the lower animals is still an open question. 

 At present we possess insufficient data for its determination, 

 and the subject is one of those which offer themselves to 

 the scientific and experienced veterinarian for full investi- 

 gation. 



