208 Zoology of Colorado 



The tongue is short, as in Colletes. There are only two cubital 

 cells; the stigma is well developed and the marginal cell is pointed. 

 These little bees nest in the dead stalks of various plants; from 

 such material it is possible to breed not only Prosopis but also 

 the little dark green bees of the genus Ceratina, of which we have 

 three Colorado species. 



The study of wild bees still affords great opportunities for 

 research and discovery. In the summer time, as we travel 

 through the mountains or across the plains, the flowers are alive 

 with butterflies and bees. The butterflies, beautiful and inter- 

 esting as they are, resemble the birds in having been rather 

 exhaustively studied. There is, indeed, much work to be done 

 on even these well-known groups, but the species have been 

 described, and the distribution and habits are rather accurately 

 known. With the bees it is a different matter. There have been 

 few students, and it is still possible to discover new species even 

 in Boulder, where I have paid attention to this group for twenty 

 years. Many new facts about distribution are continually 

 coming to light. Very much remains to be done in breeding the 

 insects, describing their habits and matching the sexes. The 

 host-relations of our parasitic bees are hardly known at all. Many 

 important details of structure are still to be described and illus- 

 trated. The larvae of the bees have good characters, but we know 

 little of them. Various remarkable insects of other orders are 

 parasitic on bees, and these should be bred and studied. Un- 

 fortunately there is at present no manual of North American bees, 

 though there are numerous revisions of particular genera or parts 

 of genera. Were a manual to be prepared today, as complete as 

 we could make it, it would soon be out of date, owing to fresh 

 discoveries. It is pleasant and convenient for the student to 

 find a book which will solve all his difficulties, but when he finds 

 this, it means that the work has already been done. To the real 

 naturalist it is more agreeable to be a pioneer, treading the little 

 known paths where discoveries may be made every day. 



