Ailanthiculture. 199 
I saw finished on my visit there in the last week in September. If 
housed but not forced, the moths will probably begin to hatch out 
the last week in May and during June; but if they pass the winter 
out of doors, not till the end of July. A higher or lower temperature 
hastens or retards their development and growth in all their several 
stages: below 50° F. they are dormant; above 50° and below 
70° their growth progresses steadily and healthily; above %0° 
their vital activity is greatly accelerated, and the duration of their 
several stages is proportionately lessened. Of this important 
character of constitution | have observed so many instances as to 
be thoroughly convinced of its existence and value as regards 
English Ailanthiculture. 
For a day or two before emerging the pupa case stiffens, turns 
a dark colour, and shows the white streaks and ocelli on the body 
of the enclosed imago ; then when the weather seems likely to be 
fine and favourable the pupa case splits open at the top of the head, 
and by the struggles of the insect is gradually pushed down ; 
little by little the insect emerges, dilating the aperture at the apex 
of the cocoon which has been left for an exit; the elastic walls 
serve as a means whereby the pupa case may be forced backwards 
and got rid of, It is a quaint and curious sight to see the pretty 
creatures emerge and spread their wings. We will suppose the 
chaplets of cocoons strung up ina green-house at a temperature of | 
90° in the first week in June, with a south-west wind; a shower in 
the morning has moistened the air (or if not, man has supplied the 
desired moisture by syringing with a hydropult the floor and walls 
of the green-house); at 4 o’clock, p.m., there are no insects out, 
5 o'clock and none emerge ; we now go in to tea; at 5°30 there are 
two out, with wings soft but fully developed, one a magnificent 
female of a tawny-yellow colour; three more have but just 
emerged, as may be noted by their tiny wings, curiously curved 
and bellyed out ; and now if we watch we shall have a good chance 
of seeing one escape from its winter prison, and become a glorious 
thing of life. See! a quiver and a shake runs through that 
chaplet! which is the cocoon wherein newly-born life struggles 
to be free? Another and another struggle and we detect the 
individual cocoon; see! a greyish-yellow face emerges, then the 
head, then a leg, then the opposite one, now a third leg; then a 
wing on the same side is partially pulled out, the shoulders being 
bent over on the opposite side, then a fourth leg (the first two 
pairs), and now bending first to one side and then another the limp 
wings are withdrawn from their cases and emerge from the cocoon, 
and then with the last pair of legs the large lax abdomen tumbles 
