246 MIXED CAUSES OF 



In confinement the orang suffers from ennui, passing into 

 melancholia, according to Pierquin, who describes nostalgia 

 as one of the commonest results of captivity in other 

 animals. The captive eagle is sullen and ferocious, while 

 mischievousness is developed in the elephant and other 

 animals (Watson). 



Captivity involves want of mental, as well as of physical, 

 exercise, perversion of many of the normal functions of free 

 or healthy life, the non-gratification of the natural desires, 

 abnormal conditions of temperature and light, and frequently 

 monotony and solitude. Pierquin has dwelt on the influence 

 of confinement in modifying animal character, artincialising 

 and demoralising it. 



But care must be taken not to overrate, as a factor either 

 of bodily or mental disease, the importance of that element 

 in captivity which consists of a sense of the mere deprivation 

 of liberty, of the loss of personal freedom. Tor confinement 

 is not in all cases enforced, involuntary, or punitive. Some 

 animals are quite indifferent to confinement, to the depriva- 

 tion of freedom (Adams) . There are cases of others which 

 have been liberated, or have escaped, and which, having 

 presumably contrasted the benefits of domestication, for 

 instance, with the disadvantages of the wild or free state, 

 voluntarily return to a pleasant captivity. 



It has yet to be determined how far wild and domesticated 

 animals are, in proportion to their relative numbers, subject 

 to insanity ; and what in each class is the form, frequency, 

 and causation of the insanity. 



Miss Buist tells us that certain cage birds prefer solitude 

 to society. We know that certain animals are naturally 

 solitary or non-social, e.g. the common hyaena and the puff 

 bird (Baird) ; and self-isolation, or aversion to society, is a 

 common feature of disease mental and bodily in many 

 animals. But, as a rule, the society of their fellows, or of 

 man, is necessary to their mental comfort. There are some 

 animals more especially certain dogs that care little, or 

 not at all, for the companionship of their own species, but 

 that have formed the strongest possible attachments to man. 

 In such animals the want of the society of a loved master 



