426 THE BIRDS OF PARADISE [ch. xxxvin. 



species, which are less sought after by amateurs, but are a 

 more profitable merchandise. The same causes frequently 

 lead the inhabitants of uncivilized countries to conceal 

 minerals or other natural products with which they may 

 become acquainted, from the fear of being obliged to pay 

 increased tribute, or of bringing upon themselves a new 

 and oppressive labour. , 



