No. 145.] 
851 
had for many years advanced but little in size, and some of their 
limbs were annually perishing and falling to the ground. And 
in every instance where a tree was infested at all, it was badly 
infested ; and the wood of the hickory which is so much esteemed, 
and for particular uses is so valuable in consequence of its tough¬ 
ness and elasticity, when once attacked by these borers and the 
ants which succeed them, becomes so extensively perforated and 
mined as to be worthless for anything except fuel. 
The burrow of this worm is excavated in the solid heart-wood 
of our American hickories and walnuts, and is almost two feet ia 
length. It runs longitudinally upwards, in¬ 
creasing in diameter as the worm has increased 
in size. The anuexed cut gives a view of por¬ 
tions of two of these burrows much reduced in 
size. The hole which the worm bores is some¬ 
what flattish, or more wide than high, and in its 
largest part it is nearly half an inch in width, 
and considerably over a quarter of an inch in 
depth. At its upper extremity it turns obliquely 
outwards through the sap-w;ood to'the bark. 
All the lower part of this gallery is tilled with 
a fine powder, of a tan color, the castings of the worm ; and some 
two or three inches below its upper end, in plaee of tliese fine 
castings, it is stuffed for a distance of an inch and a half, or more, 
with a coarser material, namely, short fibres of wood, which are 
bent and packed together commonly in a perfectly regular man¬ 
ner. Above these is another layer of the finer castings, the upper 
end only of the burrow being vacant. And I presume this borer, 
like that of the apple tree, having completed its burrow and 
opened it out to the bark, retires backwards a short distance and 
stuffs the upper end of the cavity with its castings, having the 
castings above it and the cushion of coarser woody fibres imme¬ 
diately below' it during its inactive larva and its pupa state— the 
coarser fibres being placed there as a bed for the pupa to lie 
upon—-by their elasticity yielding to any elongation or other mo¬ 
tion of the slumbering insect, which the fine castings woufM 
become too compact and solid, by their settling together, to per- 
