METHOD OF DETERMINING GENERA. 
183 
in Osmia and Saropoda, four; in Chelostoma and Cceli- 
oxys, three; in Anthidium and Megachile , etc., two; 
and in Epeolus 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. 
