NOTES AND OBSERVATIONS. 63 



simple obsGrvations are better, and (if accurate) must yield far truer 

 results, than any theorising, however plausible the latter may appear. 

 I think that the point has been determined in the case of bees ; but I do 

 not recollect having heard of any systematic series of similar observa- 

 tions on butterflies or moths, and I am sure that such would be quite 

 worth making. Since in all departments of science one branch is con- 

 tinually encroaching on those around it, and since this seems to be 

 especially the case with the kindred branches of zoology and botany, 

 I do not think it is necessary for me to make any apology for intro- 

 ducing a note dealing largely with botanical subject-matter in an 

 entomological magazine. Eeferring again to Mr. Shaw's most inte- 

 resting paper, I do not think that the Viola in question was necessarily 

 more attractive to humming-bird hawk- moths in general than the 

 double geranium, but merely that this particular specimen had acquired 

 a taste for that particular kind of nectar on the day in question. — F. P. 

 Bedford; 326, Camden Eoad, N., January 2nd, 1894. 



I was much interested in reading Mr. Shaw's notes upon the habits 

 of Macroylossa stelhttarnin [ante, p. 21). It is a striking instance of the 

 chromatic sight of insects. The occurrence he observed is, I think, in 

 opposition to the general rule, viz., that inconspicuous flowers are less 

 fertilised by insects than bright-tinted ones. Perhaps the honey-cells 

 in the particular flower of which he speaks are so placed as to be out 

 of reach of the ordinary bee, and have by Natural Selection become 

 specially suited to the taste and habits of night-feeding insects. If 

 this were so, their pale cream-colour would render them more conspi- 

 cuous at night than the darker-hued blossoms, causing them to be more 

 frequently visited, and therefore fertilised by moths and other night- 

 flyers. Although M. stellatarum is a day-flying species, it perhaps still 

 retains the same tastes as the nocturnal moths. Also, it would doubt- 

 less find the nectaries in a moth-fertilised flower in a position better 

 suited to the shape of its trunk than in those of any bee-attracting 

 varieties. There are some species of Viola which, as Darwin men- 

 tions, are dimorphic in their flowering ; that is, with some flowers 

 devoting all their efi"orts to attract insects, so as to secure the advan- 

 tages of crossing ; while others, by growing entirely self-fertilising, 

 prevent the species from becoming extinct, in the event of an absence 

 of bees and other honey-feeders. Is it not possible that the bright 

 colours of some of the species of Viola have at a former time been 

 evolved for the purpose of alluring insects, but that these agents, having 

 from some cause or other become scarce, have compelled the plants to 

 make themselves independent of outside help, by becoming self- 

 fertilisers ? Then, although the nectarial glands, through their causing 

 a waste of energy, may have gradually diminished, the colours of the 

 petals — by not exerting an influence, either for good or bad, over the 

 welfare of the plants — may have been allowed to remain in their old 

 conditions. I should like to know if Mr. Shaw's plants differed in 

 any marked degree in the internal structures of their flowers, and if 

 all or any part of them were visited by other insects. — Alfred J. 

 Johnson ; Boldmere, January, 1894. 



Glyphisia crenata. — In your notice of the Burney sale, you mention 

 that two examples of this rare species only brought 8s. and 10s, 



