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After a brood, or rather colony, has been reared in one part of a stump, 

 another part, which has mean time reached the proper condition, is often attacked 

 the following year. So that it may happen that one part of a stump is quite 

 rotten, whilst another is still tenanted by the beetle; but wherever there are 

 larva? still feediQg, the wood continues apparently sound. 



There is anuther point which seems important, that is, the position of the 

 stump. I hare rarely found them io stumps on level ground, but nearly always 

 in those on a steep slope. This probably arises from the earth above yield- 

 ing a supply of moisture to the latter, whilst there is sufficient drainage 

 below to prevent their being waterlogged, and the wood is thus kept of a 

 proper dampness. lb must, moreover, arise to some extent from stumps on a 

 slope presenting on the lower side an abundant surface, from which the beetles 

 can make their attack ; as they always bore inwards horizontally or slightly 

 upwards, they thus command nearly the whole stump, whereas with a stump 

 whose surface is level with the ground they can command very little of it. 



During July and August P. Ci/lindrus emerges from the pupa state, the 

 greater number during the last week in July, and at this period they commence 

 their burrows; on July 15th I found such a burrow nearly three inches in 

 depth. Occasionally an odd burrow is to be found, but usually the burrows 

 are in colonies, and as many as fifty entrances may be found on the side of 

 a stump, scattered over a surface twelve to fifteen inches wide and four or five 

 high. The burrows are often begun on a smooth surface, but usually any little 

 hollow or irregularity is taken advantage of in commencing the burrow. I have 

 a fine specimen, in which a strip of bark had been removed from the side of a 

 large root, and the margin was cicatrising ; in the angle all round this surface 

 the entrances of burrows were closely placed, only one or two others being pre- 

 sent at other points. The burrow from its mouth on the surface of the stunip 

 is a perfectly clean-cut cylinder. 



Each burrow is tenanted from its commencement by a pair of beetles. 

 Both beetles and full-grown larvse feed on the wood, and when they are doing 

 so, they eject little rounded nodules of frass, which have obviously passed 

 through their alimentary canals. In the case of Hylesinus Fraxini, and 

 several other Xylophaga, I have satisfied myself that the parent beetles eat 

 the removed material when they are forming their burrows of oviposition. 

 "With P. Cylindrus, however, this is not the case. In forming it3 burrows it 

 does not eat the removed material, and instead of the end of the burrow being 

 rounded, it is at this period flat, i.e., a plane at right angles to the axis of the 

 burrow ; and the ejected frass is not found in the little rounded pellets after- 

 wards or served, nor in little lenticular bitten pieces, which appears the only 

 other alternative, but in very fine splinters, most of them of a length equal to 

 the dian eter of the burrow. I may remark here that this burrow is always 

 made across the fibres of the wood. The ejected frass, which forms a little heap 

 outside the burrow, looks very different from that afterwards thrown out. Both 

 sometimes accumulate to such an extent as to bury the mouth of the burrow, 



