A FEATHERED PARASITE* 



NOTHING could more clearly prove that a common 

 law runs through the whole domain of Nature 

 than the fact that in every division of her realm 

 there seems to be a class of parasites. In the vegetable 

 world, as is well known, there are various plants that 

 depend wholly on other plants for the supply of their 

 vital forces. And in the human sphere there are parasites 

 in a very real and literal sense men and women who 

 rely upon the toil and thrift of others to sustain them 

 in worthless idleness. 



In view of the almost universal character of this law 

 it would be strange if these peculiar forms of dependence 

 did not appear in the avian community. We do find 

 such developments in that department of creation. 

 Across the waters there is one bird that has won an 

 unenviable reputation as a parasite : the European cuckoo 

 relies almost wholly on the efforts of its more thrifty 

 neighbors to hatch and rear its young, and thereby 

 perpetuate the species. Strangely enough, our American 

 cuckoos are not given to such slovenly habits, but build 

 their own nests and faithfully perform the duties of nidi- 



*Reprinted from Appleton's " Popular Science Monthly," with additions. 



72 



