40 ^•'"'y' 
plants to shoot above it, it has at once a snug place of concealment ; and then the 
upper part of the plant being bent down, or inverted, while the larva still attaches 
itself to what was the upper side of the leaf, it is effectually protected from rain 
(for none of these plume larvas, I think, like wet) ; and, lastly, when it is full 
grown, a very stiff short stem of its own preparing, nicely covered over so that the 
wind cannot disturb it, is ready for it to afl^x itself to before becoming a pupa. — 
N. Greening, Warrington, May 20ih, 1867. 
*^* I have this day (14th June) reared the perfect Pt. hieracii from larvae with 
which Mr. Greening most kindly supplied me. — H. G. K. 
Notes on variation in Lepidoptera. — Having read with much interest the articles 
on variety-producing, I am induced to offer a few observations. 
As to the action of light producing variation in a state of nature, either through 
the larval or pupal stages, I cannot subscribe to it. Practically, it is well known 
that, as a rule, most larvae retreat from light instinctively ; and as for pupse, unless 
they be " surface changers," light cannot affect them. 
As for length of time passed by the insect in the pupal state making any 
difference in the future imago, my experience is decidedly opposed to it. I have been 
a " forcer," and to a very large extent, some thirty years, but, out of thousands of 
" short-timers," have never reared any varieties. Last year, a man who collects 
for me got a second brood of A. Caja, but there was no variation; another had 
several broods in rapid succession of N. plantaginis, and also of E. russula, but no 
varieties ; and treble broods of S. lunaria produced nothing out of the ordinary way, 
Another had treble broods of A. subsericeata, which begat mancuniata, because they 
were " hungered " into dwarfs, some of them no larger than osseata. In fact, all 
my observations have tended to one point, viz., — that variation is caused by 
disease, brought on mainly, if nou wholly, by starving the larva, which causes the 
bulk of varieties to be more or less crippled. Last year I looked over an immense 
number of V. urticw, bred by a good feeder, and there was not a variety amongst 
them ; while another man had got what they call a swarm, and let them starve or 
eat the band-box in which they were kept, if they would, and out of the sur- 
vivors he bred a good many buff varieties, others with strong black nervures 
through the wings, others wanting the two spots entirely. Indeed, I got more 
varieties from that one man than I had ever seen before. I questioned him only 
yesterday, and he said there were a great many cripples among them. Again, 
another friend had a lot of hetularia eggs ; the larvae were feeding up well, when 
he had occasion to go from home, and when he returned he found a number of 
them dead, and the rest all apparently too weak to change to pupa. He put some 
soil in the box, and they managed to vsriggle in, and some forty odd changed, which 
produced twenty black males and twenty intermediate (half-mourning) females. 
Respecting 8. illustraria, I have never bred it myself, but a friend of mine at 
Cockermouth reared a large number ; a second brood was delunaria, and a third 
brood was delunaria. 1 have had illustraria from Perthshire, and have seen 
Norwegian specimens ; but I never saw delunaria from either of these places, 
though the same transformation may go on as at Cockermouth. I hardly think 
that the " long term " principle has anything to do with variation. 
