METHOD OF DETERMINING GENERA. 183 



in Os:nia and Saropoda, four; in Chelostoma and Coeli- 

 oxys, three; in Anthidium and Megachile, etc., two; 

 and in Epeoltis and Apis but one. 



In this collocation no incidental peculiarity beyond 

 diversity is apparent, for in the first instance a parasite 

 and a bee not parasitical are associated ; and in the last, 

 a parasite is associated with the bee which has the most 

 elaborate economy, and the most largely developed in- 

 stinct of all known insects. Nor are, in any case, those 

 parasites associated by these means with their own sitos, 

 or insect upon which they are parasitical. 



Thus encouragement attends the beginner at the very 

 outset of his study ; and the prospect of a wide field for 

 discoveries, in many directions, lies open to him, to 

 excite his curiosity and to stimulate his industry to the 

 pursuit of higher aims than the mere accumulation of 

 species. 



