PRODUCED BY MENTAL CAUSES. 259 



the love of his mistress, a male chocollito (a South American 

 parrot), distressed by the conjugal infidelity of his mate, a 

 pet bull dog from jealousy of a rival, all died of heart-break 

 (Wood). 



* Found dead ' is very common in the lower animals, for 

 instance in pet birds, and many of these cases of sudden 

 death unexpected by man are no doubt the result greatly 

 of emotional causes. But, as in man, there are also many 

 physical causes of sudden death among the lower animals, 

 and we must not therefore set down all cases of animals 

 6 found dead ' to heart-break or other emotional disorders. 



The popular belief in the connection between cardiac 

 conditions and emotional states is variously illustrated as 

 regards the lower animals. We speak, figuratively of course, 

 but quite legitimately, of soreness or sickness of heart in 

 such animals as the dog, horse and elephant. A lost dog is 

 properly said to be heart-sore from the severance of the ties 

 of affection, while if it be at all sensitive, it is ' disheartened ' 

 by rebuffs of all kinds. And, on the other hand, while emo- 

 tion produces cardiac disturbance, the converse holds equally 

 good that cardiac disturbance produces abnormal emotional 

 states. Thus Pierquin has pointed out the relation between 

 cardiac derangement or heart-lesions and the development of 

 morbid fear of every degree up to panphobia. 



Cardiac disorders would therefore appear to be both 

 causes and effects of mental excitement and depression. The 

 relations of cardiac to mental derangement in the lower 

 animals are not, however, at present well known, and I 

 venture to suggest them, as an admirable subject for ex- 

 perimental investigation equally to, and by, physicians and 

 veterinarians. 



We have already seen, moreover, that the expression, 

 ' broken heart,' is not always or necessarily figurative, whether 

 in the lower animals or man, in so far as various organic 

 lesions of the heart, including rupture of its walls, occur 

 occasionally as the result of intense passion or emotion. 



Further, various functional disorders of the heart's action, 

 connected no doubt in many cases with organic changes in 

 its structure, are not uncommon, as the fruit of emotional 



s 2 



