Ailanthiculture. ~ 201 
the transverse white streak at its upper margin, and curving round 
to intersect the inner margin of the wing, which is very fully 
feathered. 
The falcation of the upper wing is most strongly marked in the 
male; in the female the under wing is broader and fuller, the 
better to support in flight her weighty abdomen. 
Expanse of wings 5 to 6 inches. 
It is quite a mistake to suppose, as is often alleged, that pupa, 
if taken out of the cocoon and left to themselves, cannot produce 
insects. If the pupe are kept moist, the insects will in due time 
be born, and go through exactly the same process as above de- 
scribed; but not having the help of the cocoon to push back the 
pupa case from their lax wings, they frequently manage to get 
only two or three wings free, and the pupa shell remains attached 
to the fourth wing (generally an under wing), which therefore is 
never developed. From this cause many insects are crippled if 
taken out of their cocoon before birth; and when once crippled 
they seem to possess no sexual power or desire, and are incapaci- 
tated alike for flight and copulation ; for I have found by repeated 
trials that coition among cripples rarely if ever takes place. 
If the weather is changing from a lower to a higher tempera- 
ture, the moths will emerge more freely, and even anticipate such 
a change; if however it be falling to a lower temperature they do 
not come out so well. One night, 29th August, 1862, two males 
and two females emerged (second crop), the thermometer being 
65° F. in the greenhouse. On the 27th eleven, and on the 28th 
fifteen had emerged, so that I could not understand the sudden 
diminution: but during the night, which was cold and dewy, the 
temperature fell. Of four pairs put together to copulate, only 
two pairs were found joined in the morning, which was quite un- 
usual, The following morning however was warm and sunny, and 
at 9 a.m. when I entered the greenhouse I found (which also was 
quite unusual) seven newly-born imagos; during that day eleven 
more moths emerged. It was, therefore, quite plain that the 
changed temperature, before it was perceptible to man, operated 
so as to prevent the exit of the insects at the usual hour. It also 
to a certain extent prevented coition, and this happened more 
or less-so frequently that I was almost enabled to predicate a 
shower or a cold night by the absence or presence in abundance 
at the usual hour of newly-born imagos. 
The usual hour of exit from the cocoon was from 6 to 8 p.m.: 
some however would be born during the night, and were found 
expanded and quiescent in the morning ; some few also were born 
VOL, V, THIRD SERIES, PART 11.— APRIL, 1866, P 
