DIFFERENCE AND DISORDER. 191 



in a great variety of animals for instance, the cat are 

 also themselves states of excitement. 



The singular likes and dislikes of certain animals may 

 rather be said to amount than to give rise to genuine mental 

 disease. The cat-bird of North America has such a dislike 

 for the Felinae that it at once shows strong excitement in their 

 presence. It has no fear of the dog. But it has a marked 

 dread even of the skin of the hare (Dr. Adams) a morbid 

 imagination probably operating to its mental disturbance. 

 The fear of intruders in mining wasps gives rise, or amounts, 

 to considerable mental excitement. It is morbid : moved by 

 a disordered imagination, a groundless dread, they make 

 repeated examination for supposed or possible intruders, a 

 procedure which, under other circumstances, might be de- 

 nounced as senseless and useless, amounting to, or indicative 

 of, stupidity or error (Duncan). The sexual furor readily 

 passes into a true love-madness ; desire or appetite gets 

 beyond the bounds of control, especially if its gratification 

 be opposed or prevented, while mania, melancholia, or 

 dementia may result. Maternal love sometimes amounts to, 

 rather than engenders, frenzy in the presence of danger to 

 offspring (Pierquin). Habitual suspicion or suspiciousness, 

 while it paves the way for delusion, is itself usually a mor- 

 bid mental state. 



The question, in short, is very much one of degree. Thus 

 anger may exist in all the degrees of irritability or irasci- 

 bility, passionateness, or excitement : while it is just as apt, 

 as in man, to become excessive, pass beyond control, assume 

 a morbid and dangerous character, and develop or degene- 

 rate into ungovernable fury or ferocity, which in its turn is 

 but a stage short of acute mania. 



Again, supposed causes may be mere results, concomi- 

 tants, or complications instead of antecedents. Causes and 

 complications, for instance, are apt to be confounded. Co- 

 existing bodily disorders are common, which may aggravate 

 insanity, though they have not originally produced it for 

 instance, tubercle in the lungs or other parts of the body, 

 exhausting discharges, hydatids or other tumours in the 

 brain. 



