113 



are probably of great assistance in locomotion. The young larvae adhering 

 to the damp felty wall of the burrow by its moisture, moves freely along it 

 or round it by a wavelike motion, and feeds entirely on the fungus exudation 

 until it has grown large enough to occupy the whole diameter of the burrow. 



The full grown larva presents corneous points at the same situations as 

 those occupied by the bristles of the young larva. "With each change of skin 

 they become shorter, till they are thus only represented in the last skin. I 

 need not describe the full grown larva which has been figured by both Ratzeburg 

 and Perris, and well described by the Litter in the Annales des Sciences Nat. 

 Series II., Tome 14, p. 89. The only exception I would make to Perris's descrip- 

 tion is that he describes it as rather thickened beyond the middle, and he so 

 figures it. The larva is really quite cylindrical when at home in its burrows. 

 Perris does not appear to have met with it plentifully, and to have made his 

 descriptions from specimens removed from the burrows, without noting that soon 

 after removal the larvae became rather thicker beyond the middle segments, 

 and instead of continuing straight became curved, and then much resemble 

 the larvae of the other Xylophaga. They are extremely muscular, and this 

 change probably results from their contortions not being counteracted by their 

 usual points of resistance, the walls of the galleries. 



The larvae must feed up very rapidly, as I find full-grown larva? in the 

 burrows when they can hardly have been made more than a few weeks. I 

 have found no evidence of eggs being laid after the late autumn ; and during 

 the winter the burrows contain full-fed larvae. The parent beetles also livo in 

 the burrows all winter. During the winter all the inhabitants are nearly dor- 

 mant, but in autumn and spring much frass is ejected. 



At first and before there are any larvae in the burrow this is all of the 

 splintery variety, but afterwards it is entirely the small pellets of digested 

 wood, and consists almost entirely of the excreta of the larvae. The young 

 larvae certainly live on the fungus exudation I have described until they grow 

 large enough to fill the burrow. The large larvae must still do a deal of eating, 

 both from the amount of fat they store up and their muscularity. There is also 

 much frass ejected, and these considerations lead me to believe that the full 

 grown larvae eat the wood, though I have no proof of it, and I know that they do 

 eat the fungus. 



I think it is also evident that the various branches of the burrow are in- 

 creased 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 larva themselves, both because the parents are frequently dead 

 at this period, and the amount of excavating during a brief period must be very 

 great, more than the parent beetles could overtake. I believe that the parent 

 beetles die usually in the following April or Slay, after the larva are full fed, but 

 before the pupal cavities are commenced. 



