6l2 



THE POPULAR SCIENCE MONTHLY. 



sentatives of Johns Hopkins to hurry up 

 their proposed Mathematical Journal, that 

 there may be a proper place for the con- 

 sideration of questions like this. 



INSECTS AND FLOWERS IN COLORADO. 



To the Editor of the Popular Science Mordhly 



The communication of Mr. Meehan, in 

 your January number, and the request at 

 its close, are herewith responded to by the 

 entomologist in question one to whom we 

 may fairly apply the line 

 " [Though] young in years, in sage experience old." 



As the letter supplies the information called 

 for, you will, doubtless, wish to print it in 

 full, and I inclose it for that purpose. 



Very truly yours, Asa Gray. 



Cambridge, Mass., January 22, 1877. 



Dear Dr. Gray : In the January num- 

 ber of The Popular Science Monthly, 

 Mr. Meehan takes some exception to your 

 note in the American Journal of Science 

 for November in regard to the comparative 

 abundance of insects and flowers in the 

 Rocky Mountains of Colorado. He asks 

 particularly for a " list of the Hymenoptera 

 and Lepidoptera that are abundant enough 

 in the particular part of the Rocky Moun- 

 tain region covered by [his] experience, to 

 probably act as cross-fertilizers of flowers, 

 noting those which may perhaps be intro- 

 duced since 1871." The route referred to 

 is " through Golden City and Idaho Springs 

 to South Park, thence to Pike's Peak and 

 the Garden of the Gods. ... to Denver over 

 the level plateau known as the ' Divide.' " 

 In 1873 he speaks of having visited Gray's 

 Peak, and must, therefore, have passed up 

 Clear Creek and through Georgetown. In 

 1872 I spent three months in the moun- 

 tains of Colorado in company with Dr. C. C. 

 Parry. We walked up through the canon 

 of Clear Creek to Idaho Springs, George- 

 town, and Empire City. At the latter place 

 we established our headquarters, and there 

 most of my collecting was done. Frequent 

 trips were made to the neighboring moun- 

 tains and canons, including the ascent of 

 Gray's Peak. In the fall a trip was made 

 to Middle Park. The summer of 1873 I 

 spent in Western Wyoming with Captain 



Jones's exploring party. In 1874 I again 

 visited Colorado, but spent most of my time 

 on the plains at the base of the mountains 

 between Boulder City and Canon City, 

 though I made several trips into the moun- 

 tains up Boulder, Left Hand, and Clear 

 Creeks. In 1875 I spent some time in Utah 

 among the Wahsatch Mountains. It has 

 always been my experience that, wherever 

 flowers were plenty, so were insects. Con- 

 sequently, I have always found a botanist 

 to be most excellent company on a collect- 

 ing-trip. As my opportunities were better 

 in 1872, my remarks refer mostly to that 

 year, and it is not at all likely that any of 

 the species I then noticed had been intro- 

 duced. Lists of the Coleoptera, Lipidopltra, 

 Hymenoptera, and Orthopiera, collected on 

 this trip, have been published in the "Pro- 

 ceedings of the Davenport Academy of Nat- 

 ural Sciences," vol. i. ; but I will here call 

 attention to such of the species as seem to 

 be most useful in the fertilization of plants : 



Hymenoptera. Bomhus Jtavifrons (Cr.) 

 was perhaps the most common and gener- 

 ally distributed of the bees, though it seems 

 to be quite a mountain species. I always 

 found it wherever there was a patch of flow- 

 ers in an opening in the timber, or at the 

 timber-line. I did not notice that it con- 

 fined itself to any particular kind of flower. 

 It may have done so, but I do not remember 

 it. In company with the above, though 

 somewhat less abundant, I found B. tcrma- 

 rius, the species mentioned by Mr. Meehan 

 as confining its attention to Polygonum bis- 

 iorta, but I did not notice this peculiaiity. 

 Both of these species were found abundant- 

 ly at Empire City and on the surrounding 

 mountains. Besides these, Bombus boroilis 

 (Kirbv), Apalhus insularis, Anihophora tcr- 

 ?ninalis, Megachile gentilis, Menumetha bo- 

 realis, were found in abundance in the dis- 

 trict referred to by Mr. Meehan. Of other 

 Hymenoptera collected in this district, I men- 

 tion the following, which probably were of 

 more or less assistance in the fertilization 

 of plants : Calliopsis (sp. V), Prosopis affinis^ 

 Agapostemen texanus, Collctes consorx, Ves- 

 pa diabolica, AmmopMla luctuosa, A. com- 

 munis, etc., besides a considerable number 

 of smaller species as yet undetermined. 

 For a more complete enumeration, I must 

 refer you to the list above mentioned. To 



