Platypodine.] RHYNCHOPHORA. 451 
Each burrow is tenanted from its commencement by a pair of beetles; 
both the beetles and full-grown larve feed on the wood, and while doing 
so they eject little rounded nodules of frass which have obviously 
passed through their alimentary canals; Hylesinus fraxini and other 
of the Xylophaga eat the removed materials while forming. their 
burrows, but this is not the case with Platypus; while forming its 
burrow it throws out the removed wood in very fine splinters which 
may easily be distinguished from the frass of the wood that has served 
it for food. Dr. Chapman (l.c. p. 105) gives a very long and interest- 
ing account of the process of splintering the wood, and suggests, with 
much reason, that the usual absence, or rather broken condition of the 
tarsi in older specimens is due to their method of working; as is well 
known, the tarsi of fresh specimens are very long and slender, but very 
soon become much shorter; Dr. Chapman suggests that at first they 
may be very useful to the beetles to enable them to suspend the body in 
a proper position at right angles to the surface of the wood or bark in 
commencing their burrows. 
When the burrow is some six or seven inches in depth a rounded 
extremity is made to it, in which the female deposits her eggs, and it is 
for the time abandoned, the parent beetles commencing the construction 
of a branch ; eggs appear to be laid as early as the beginning of August, 
and as late as the end of October, and, as arule, in recently constructed 
branches of the burrow ; when hatched the young larve feed on the 
fungus above mentioned, and do not begin to eat the wood until almost 
full grown, when they probably attack it; when newly hatched the 
larve are not straight and cylindrical like the full-grown larve, but are 
rather flattened and dise-shaped, the lateral region being largely deve- 
loped, and each side carrying two rows of large stiff bristles, each 
bristle surmounting a lateral tubercle; these bristles are evidently of 
great use in locomotion; by their means the larva moves with 
great ease up and down among its fungus food until it has grown large 
enough to occupy the whole diameter of the burrow; with each change 
of skin these bristles become smaller, until in the full-grown larva they 
are only represented by corneous points. 
The larvee feed up rapidly as they are full-grown before the winter ; 
in spring they excavate the pupal galleries on either side of the ordin- 
ary burrows ; these are close together, the two sides of a burrow often 
containing several dozen within a few inches, and are always at right 
angles to the gallery from which they start ; 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; 
when the perfect beetle emerges, it soon leaves the burrow, and 
either forms a fresh burrow in the stump, or takes wing to a fresh 
locality. 
The beetles are able to stridulate audibly, by rubbing the abdomen 
rapidly against the elytra; when a log containing a number of burrows 
Ge 2 
