ENTOMOLOGICAL INSTRUMENTS, &C. 555 
cover and do well. You will often meet Lepidopterous 
larvae travelling over roads and pathways : at such times 
they have usually done feeding, and are seeking a spot 
in which they may assume the pupa with safety. These 
you may place in one of your cells, and they will select 
a station for themselves. You must be careful frequently 
to examine the boxes in which you have pupa?, that you 
may take the imago as soon as it appears, and before it 
has had time to injure itself in attempting to escape. I 
mentioned to you on a former occasion Reaumur's expe- 
riments to accelerate the appearance of the butterfly a ; — 
there is another still more remarkable, to which he had 
recourse for this purpose : it was by hatching his pupae 
under a hen ! ! You will wonder, perhaps, how this 
could be effected, and be disposed to maintain that the 
pupae must be crushed by the weight of the brooding 
animal. How did the ingenious and illustrious expe- 
rimentalist prevent this ? He prepared a hollow ball of 
glass, open at one end, about the shape and size of a 
turkey's egg. Having several chrysalises of the nettle- 
butterfly (Va?iessa Urticce) suspended to a piece of paper, 
he cut out some of these singly, with a square portion of 
the paper attached to them, and covered with paste the 
side opposite to that from which the chrysalis was sus- 
pended : these he introduced into the ball through the 
aperture, placing them as near to each other as possible, 
taking care so to apply the pasted surface to the inside of 
the ball, that when the side to which they were fixed was 
uppermost they all hung as from a vault. This being 
done, he stopped the aperture with a linen plug, but not 
a Vol. III. p. 262-. 
