$2 | September, 
fluid to moisten their cocoons, and loosen their texture to facilitate emergence. 
Though the matter is now to be regarded as open to no doubt whatever, some 
details of the process may be interesting. I confess that I was once inclined to 
doubt the fact, assuming that the moths that were said to do so had no mouth 
apparatus for the purpose ; for it is precisely those moths that have no proboscis and 
hardly any oral appendages that soften their cocoons with a special fluid. 
I have examined several specimens of P. Cecropia at the moment of emergence, 
having first taken the pupa out of its cocoon; as soonas the chrysalis case bursts, the 
head of the perfect insect appears—this is clothed in frout with red hairs, bounded 
behind by the grey wool of the collar (prothorax). These red hairs are seen to be 
moist, and as soon as the vertex is all visible it becomes quite wet. If this fluid be 
removed, it is replenished to a total amount of more than one minim. What is most 
striking in examining the insect in this way is that, though the wool on the head is 
as wet as a sponge, the wool of the collar and prolegs which touches it remains per- 
fectly dry. The fluid itself is colourless, faintly alkaline, and, when applied to the 
silk of the cocoon, renders it almost instantly soft, and easily teased out. The fluid 
appears not only to soften the gum that stiffens and binds together the silk, but to 
a certain extent to destroy or neutralise it, as the margin of the opening from which 
the moth has emerged remains soft and pliable, without any of its previous stiffness 
or harshness. The wetted surface of the head dries very rapidly after emergence. 
The fluid comes from an opening which must be the mouth. This is a narrow 
transverse slit, separated from the wool of the face by a narrow naked surface 
which I take to be the labrum, and prevented from reaching to the eyes on either 
side by two small projections which appear to represent the mandibles. Immediately 
below it are two rounded elevations which must be the maxillz. This region is all 
free from wool, but is covered by the palpi which are attached immediately below, 
and which are clothed with hair, as is also a narrow plate just below them (the 
labium ? ); after which is the membrane articulating the head to the following 
segment. Hach palpus appears to consist of only one joint articulated by a rather 
narrow neck, but it is difficult to assert whether it be the labial or maxillary palpus, 
though IJ incline to think it the former. In either case, I think it evident that 
the orifice from which the fluid proceeds is the mouth. 
In a note on Tipula flavolineata in the Ent. M. Mag., I described how the 
intestinal canal is inflated with air on the emergence of the insect from the pupa 
state. This appears to be a very common occurrence during the ecdysis of insects, 
though I do not remember to have seen it noted. I have observed it in several 
Lepidoptera, and in the earwig at its several moults. Thelarvaof P. Cecropia, when 
about to spin, discharges, with the last contents of the intestinal canal, from thirty 
to fifty minims of clear fluid, which soon becomes brown (especially if the larva 
have fed on apple) ; and various other Bombyces do the same: the larva, notwith- 
standing, does not diminish in bulk, but the intestinal tube is inflated with air; this 
is easily tested by scratching the tubercles of the larva, when a hollow sound results, 
hardly any sound being produced by so treating a feeding larva; and I have 
determined by dissection that the air is in the intestine.—T. ALGERNON CHAPMAN, 
Abergavenny, Juie, 1870. 
