CORRESP ONDENCE. 



361 



CORRESPONDENCE. 



INSECTS AND FLOWERS IN COLORADO. 

 To the Editor of the Popular Science Monthly. 



IN my paper on " The Fertilization of 

 Flowers by Insect Agency " (" Proceed- 

 ings of the American Association for the 

 Advancement of Science," 1875, pp. 244, 

 245), I say : " On my first visit to the Rocky 

 Mountain region, the absence of insects 

 proved very annoying to the entomologists 

 who accompanied me. Indeed, the paucity 

 of animal life of all kinds in the Rocky 

 Mountains is well known ; but there is no 

 more scarcity of seed in the colored flower- 

 ing plants than in similar ones elsewhere." 

 At the conclusion of my address, Prof. Riley 

 objected to the accuracy of this statement 

 not from his own personal experience, as I 

 believe, and from overlooking, as I sup- 

 posed, that I was referring to insects relat- 

 ing to the cross-fertilization of flowers 

 chiefly Jli/menoplera and Lepidoptera. Mr. 

 Charles R. Dodge, editor of Field and For- 

 est, was one of the entomologists I referred 

 to. In vol. i., No. 12, page 89, he describes 

 that expedition in the summer of 1871 : 

 " The route carried us through Golden City 

 and Idaho Springs to South Park, thence to 

 Pike's Peak and the Garden of the Gods, 

 where we emerged from the mountains and 

 returned to Denver over the level plateau 

 known as the ' Divide ; ' and, from the time 

 we passed the foot-hills near Golden City, 

 and entered the first canon in the moun- 

 tains, we were struck with the comparative 

 paucity of the insect fauna. ... In the 

 mountains', the marked absence of insect- 

 life in variety, except in favorable locali- 

 ties, was the rule, and not the exception." 

 Traveling was not so easy then as now, and 

 I think it took us nearly three weeks. The 

 party comprised thirty persons, all of whom 

 were interested in aiding the collectors. 

 Mr. Dodge sums up his remarks by espe- 

 cially noting that " the entire mountain-trip 

 yielded so small a number of nocturnal 

 Lepidoptera that they are hardly worth 

 mentioning." He adds, "I have conversed 

 with a few other entomologists on this sub- 

 ject, and they agree with me perfectly." 



Now, if we turn to Hayden's " Report 

 of the Survey of Colorado," for 1873, we 

 find Lieutenant Carpenter substantially re- 

 cording the same thing. Here are the doings 

 of a whole season, and not for three weeks 

 merely, and only five species of butterflies 

 are found; and, indeed, he remarks that 

 " Lepidoptera are undoubtedly peculiar to 

 high latitudes and great elevations." This 

 leaves us with scarcely anything but bees 

 to do the whole work of flower-fertilization 

 in the Rocky Mountain region. But even 

 these seem to be confined to some consider- 

 able elevation. In an expedition in 1873 I 

 saw Bombus termarius in abundance, but on 

 no other flowers than Polygonum bistorta, 

 on Gray's Peak, on the flats near the tim- 

 ber-line. I was struck by the fact that 

 they seemed to visit only this species, evi- 

 dently getting all they required from it, and 

 neglecting everything else. I did not see 

 bees anywhere in our expedition of 1871 in 

 lower altitudes, nor do I think there were 

 any in 1873, except in this high region near 

 the timber-line. Of course, there might 

 have been, but, if so, they were so scarce 

 as to attract little attention. This seems to 

 have been the experience of Lieutenant Car- 

 penter. He says, " The humble-bee was 

 always to be seen in midsummer .at the 

 verge of the Alpine flora, busily engaged in 

 collecting its store of pollen from the few 

 flowers to be found." This does not cer- 

 tainly say they might not be found lower 

 down, but it is a fair inference. My collec- 

 tions in this district embraced over seven 

 hundred species of flowering plants and 

 ferns. I can say that among these were 

 quite as large a proportion of colored flow- 

 ers as in an equal number gathered East, 

 where insects are conceded to be numer- 

 ous. 



But just here Prof. Gray steps in with 

 the following note : " A propos to Mr. Mee- 

 ban's suggestion that, although the Alpine 

 plants of the Colorado Rocky Mountains 

 are mostly high colored, insects are there 

 so rare that they can be of no material aid 

 to fertilization, and therefore these plants 



