SCIENTIFIC NOTES AND OBSERVATIONS. 179 



spell of dry weather, than on rainy nights, though these send some 

 visitors to our moth traps. The effect of light on insects seems 

 such that, once drawn within its influence, they seem hardly capable 

 of escaping. Yet we see others of the same species, pass and repass 

 the light without noticing it. As a general axiom, it may be laid 

 down that the drier the atmosphere (east winds excepted) the better 

 will be success at light. Moonlight, of course, settles the question, 

 but, given a warm night, after a dry interval, and species generally 

 swarm. I once had 45 species in my room on such an evening. 

 Moths come early, but the bulk arrive between 10 p.m. and 2 a.m. 

 One condition is, however, a mif qnil non, viz., absence of wind, 

 and, in working street lamps, such as are in a sheltered place are by 

 far the best. The cause of the attractiveness of light is a matter 

 that would well repay study. — C. Fenn, F.E.S., Lee. 



My most successful evenings at light have been damp ones ; the 

 dry ones are distinctly less successful. 8o far as I am guided by rule 

 at all, it is that I look upon wind (especially east wind) as the chief 

 deterrent to success at light. — J. C. Mobicrly, M.A., F.E.S. 



The working of light (so far as shop windows and street lamps are 

 concerned) is not very productive in this district. Only when I wish to 

 obtain Scopana cciiihrac, do I make a raid on the shop windows, and 

 then I am most successful on fine calm evenings. The electric light 

 in the works of the Steel Co. of Scotland, at Newton (near Glasgow), 

 attracts a number of Dasi/polia tcinpli, every autumn. — A. Adie 

 Dalglish. 



I have not found light pay at Portland, except in the autumn, 

 when HdiopJi()b7ts hi.yiidus, KjiuiuJa lichcnea, etc., are much attracted 

 by it ; but all specimens so attracted are males. I do not think that 

 the female of //. j^apularis is often attracted by light, though, when 

 this moth is common, the males come in great numbers. — N. M. 

 Richardson, B.A., F.E.S. 



Mr. Fenn's criticism on my " ingenious explanation " is not so 

 hard on me as it at first appears. For instance, it is because pale 

 yellow and white flowers "are more conspicuous at night" that I 

 mentioned them. It is a fact that they reflect certain rays of light 

 instead of absorbing them, as red and blue would ; these rays affect 

 the eyes of insects, the flowers are seen and visited, and a feast of 

 honey benefits the insect and fertilizes the flower : both are 

 encouraged to continue, and, a natural habit of being attracted by 

 light objects, in expectation of honey, grows up in the insect, and 

 night expansion and pale coloring are fixed in the flowers visited. 

 Coming to Mr. Fenn's moonlight criticism, I think I see neutral- 

 izing + and — signs. Thus, he says, " given a warm night," and 

 we know that to be moonlight a night must be clear, and clear nights 

 are cold nights, and insects fly not on cold nights. Again, of course, 

 given sufficient moonlight, any flower would be conspicuous, and the 

 insects so widely distributed, that to wait at any particular patch of 

 flowers for them, would not pay. I do not deny that red flowers are 

 attractive, but it is chiefly by day and often by scent, as in the 

 clover, verbena and nettles cited, which are chiefly fertilized by 

 diurnal insects. But it is only the attractiveness of light at night 

 that we are discussing, and I maintain, in answer to Mr. Fenn's 

 query — "Are white and yellow flowers the most attractive?" By 



