CH. IX. 



BIRDS. 



143 



the latter being frequently a set of mercenary and 

 ignorant men, deceived themselves and deceiving 

 others as to the kind of eggs which they offer for 

 sale ; and, instead of furthering the knowledge of 

 natural history, rendering it more obscure by pass- 

 , ing off one egg for another, and having recourse to 

 as many tricks as a horse-jockey in selling their 

 specimens, which are often bought by people who 

 have not the slightest knowledge of the natural 

 history of the bird whose eggs they fancy that they 

 are buying. 



