200 Rev. G. A. Crawshay on the 
I took two dead larvee from under bark with apparently 
their mandibles locked together. 
This would account for a given surface of bark not pro- 
ducing more than a limited number of imagos, however 
many laying 2 were deposited on it. It is not that they 
run short of food, but they run foul of each other in 
their wanderings and inflict mortal wounds on the tender 
integument. 
On the other hand, when burrowing in wood to pupate 
they will alter their course to avoid contact with each 
other, and their galleries run alongside each other with 
only the thinnest possible partition of wood-fibre between 
through which I have seen daylight. 
Under glass they show that they are fully conscious of 
their close proximity to each other, and neither will broach 
the partition. I have known three larve enter the wood 
within a in. of each other and shape their respective 
courses so as to keep clear of each other, completing their 
burrows and all three emerging perfect insects. 
I have counted as many as 59 holes of burrows in the 
surface of 1 ft. of a 7-in. larchwood-cylinder, and probably 
15 more pupated in the bark. This was a portion of a log 
oviposited on in confinement by about a dozen fertile 29, 
6 ft. of this wood yielding about 300 full-fed larvae, pupee 
and imagos. 
In thick bark I have found as many as three pupa-cells 
occupied, with a very thin layer of bark separating them. 
When the tree is large and the bark thick the majority 
prefer pupating in the bark to excavating the wood. 
THe Moutts.—The larva moults seven or eight times before 
transforming to a pupa, the moults occurring at intervals of 8-14 
days. It ceases to feed about two days before the change, and the 
soonest I have known it resume feeding after a moult was 12 hours, 
by which time a very warm temperature had sufficiently restored it 
to activity. But the usual time is a day. Before each moult the 
larva carefully smoothes the walls of the burrow. 
Appended are data of moults of larvee reared from the egg (p. 201). 
Extreme care and the closest attention were necessary to obtain 
these results, 
Unfortunately I failed to bring any of them through to the pupa 
state. I attribute this to the unwholesome fumes arising from the 
gas over which they were placed for forcing, for want of better 
accommodation, from the beginning of October when the necessary 
