THEIE PLACE IN NATURE 21 



member, it is doubtful if they can communicate 

 the disease to another species. Evidence on this 

 score is meager and wholly unconvincing. It is 

 possible, however, for them to carry the germs 

 of a disease, with which they are not themselves 

 impregnated, from one animal to another. The 

 most outstanding case of this kind is that of the 

 turkey-vulture and the pig. The vulture is a 

 scavenger, pure and simple, and feeds wherever 

 it can find carrion. To one of these birds a pig 

 which has recently succumbed to cholera is as 

 succulent a morsel as one which has died of old 

 age. The vulture can see no difference. Con- 

 sequently, upon leaving the skeleton, it carries 

 off upon its body and feathers a multitude of 

 deadly germs. 



The result is easy to follow. Upon alighting in 

 a piggery, perhaps miles distant from its recent 

 activities, the vulture unwittingly scatters the 

 germs broadcast, either through excretion or 

 by coming into contact with an object to which 

 they will adhere. If pigs are present they will be- 

 come inoculated. The remedy of course lies 

 with the farmer ; he should bury his dead stock. 



It has more than once been claimed that birds 

 are partly responsible for the spread of the 

 chestnut blight which of recent years has devas- 

 tated the chestnut forests of the United States. 

 This is not at all improbable. The blight is a 

 fungus disease which works on the inner, or cam- 



