INSANITY IN THE LOWER ANIMALS. 25 



accordingly. But the same individual may nevertheless, 

 especially when believing himself un watched, and, therefore, 

 off his guard, exhibit decided insanity of action ; and this may 

 be the only mode of its manifestation. By speech he may 

 betray himself only during unguarded moments, or when 

 self-control becomes impossible. 



Now, in the lower animals we have mainly to deal with 

 this insanity of action, the only form in which demonstrable 

 insanity exists in many men. It is only the ' overt acts ' of 

 the latter that bring their mental condition under the notice 

 of the physician, and themselves under the ban of the law. 

 In animals we have almost exclusively their acts as indica- 

 tions of insanity acts that are contrary to the usual habits, 

 nature or character, as well as to the interests, of the 

 species or individual. 



But, in some exceptional cases among animals, when a 

 certain degree or kind of speech has been one of their ac- 

 complishments for instance, in some parrots there is veri- 

 table incoherence both of ideas and words. Incoherence of 

 speech in animals that have been taught to talk intelligently 

 and intelligibly, or even to repeat phrases correctly, usually 

 betokens and accompanies the mental decay of senility, 

 though it may and does occur also in more decided forms of 

 insanity. The application of such a term as f raving * to the 

 delirium or mania of the lower animals is not, therefore, so 

 objectionable as might at first sight appear. It becomes in- 

 applicable, and simply figurative or absurd, only when there 

 is and was no power of articulate speech. 



Incongruity of action, however in the striking want of 

 relation between the acts or actions, behaviour or conduct, 

 and the surrounding circumstances or conditions in which 

 the animal is placed is an equivalent of incoherence of 

 vocal or articulate language. 



In the diagnosis of insanity in the lower animals many 

 difficulties must present themselves to the student. These 

 difficulties include the following : that of 



1 . Drawing the line between passion or anger and mania. 



The real difference one of name merely must frequently 

 be determined less by the intensity than duration of the pas- 



