134 {November, 
I think it is also evident that the various branches of the burrow 
are increased in length and complexity after the splintering process is 
finished. In the spring, also, the pupal cavities have to be excavated, 
and this must certainly be done by the larve themselves, both because 
the parents are frequently dead at this period, and because the amount 
of excavating during a brief period must be very great, more than the 
parent beetles could undertake. I believe that the parent beetles die 
usually in the following April or May, after the larve are full-fed, but 
before the pupal cavities are commenced. 
The arrangement of the branches of the burrow is somewhat 
irregular, usually consisting of a few long straight galleries that are, 
roughly speaking, parallel to each other; sometimes a branch leaves 
another near its extremity and returns nearly parallel to it, but they 
never anastomose. Sometimes they consist of short curved portions 
continuously dividing dichotomously, making, though not all in the 
same plane, a curiously regular pattern, something like a branch of 
mistletoe. The much smaller burrows of Lomicus dryographus, the only 
species we have in this country at all allied in habit to Platypus, are 
divided with much more regularity than those of Platypus. 
The principal function of the parent beetles after oviposition 
appears to be the ejection of frass from the open mouth of the gallery, 
which they alone appear to do. I have seen a small quantity brought 
every few minutes, at a season when the larve were busily feeding. It 
seems to be done by the male or female beetle indifferently. 
I have strong reason to believe that either of these directs the 
movements of the larve in the burrows, not only from the burrows 
containing eggs and young larve being kept undisturbed, but also from 
larvee falling out of the burrows from which the parent beetles had been 
removed, a circumstance that does not otherwise occur. 
The pupation cavities or burrows are excavated on either side, or 
I should rather say on the floor and roof of a straight branch of the 
burrow, tolerably close together, so that the two sides of a burrow 
often contain several dozen within a few inches. They are always at 
right angles to the gallery from which they start, and also parallel to 
the fibres of the wood, of the same width as the ordinary galleries, and 
just the length of one beetle. The larve, after excavating them, must 
come out and enter backwards, as the head of the pupa is towards the 
burrow, and the larva is unable to turn round in it. It is shut off 
from the gallery by a slender partition of frass, which looks as if it had 
got there by being pushed out of the way by passers by; and it is 
