ZOOLOGICAL DISTRIBUTION OF DISEASE, 251 



villages, unmolested and cherished by man, the traces of 

 casualties among them are so rarely seen, that the simple 

 Hindoo believes that they bury their dead by night." 



As far as my own investigations have extended I find, 

 excluding the affections known collectively as the acute 

 exanthemata (scarlet-fever, measles, small-pox, and the 

 like), that most diseases known in the human species 

 occur in mammals. A few affections rare in man are 

 frequent in mammals ; a limited number of diseases are 

 peculiar to mankind, whilst others occur only in the 

 lower animals. The inquiry is of some importance, for 

 it serves to show that certain diseases give rise to 

 changes so very different in animals of one class to 

 those of another class as to be described under a 

 different name, whilst two distinct affections may pro- 

 duce in animals belonging to different classes lesions of 

 such close naked-eye resemblance that they are fre- 

 quently confounded with each other. Such conditions 

 raise the all-important question, " How far is it probable 

 that many of the acute contagious fevers which affect 

 the human species occur in other animals, but producing 

 different symptoms receive another name ? " This is 

 illustrated in a remarkable manner by tuberculosis, a 

 disease of world-wide distribution. Writing concerning 

 that common manifestation of this disease, pulmonary 

 consumption, Hirsch, in his admirable Geographical and 

 Historical Pathology ', states that it has held at all times 

 and among all civilized peoples a foremost place among 

 the national diseases, and that it extends over every 

 part of the habitable globe, and may be designated 

 ubiquitous in the strictest meaning of the term. 



