PIN T <: BARK-BEETI ES. 
717 
upon his neighbors, he makes an abrupt turn so as to go square across 
one of these tracks. But this only serves to briug him into similar 
proximity with another track, and after this comes another and another ; 
and now he reaches a fifth oue, running in a different direction, requir- 
ing auother alteration of his course to cross it at right angles. But we 
need not follow this subject further. Others also of these galleries, 
when carefully inspected, will be found scarcely less curious. How 
wonderful is nature, that thus presents an interesting subject for our 
study in each particular track an inch or two in length which a family 
of little worms make as they eat their way along in the bark Of a tree, 
the parenchyma of a leaf, or elsewhere. How marvelous, that in such 
minute and seemingly unimportant and insignificant operations we 
invariably meet with so much to admire ! (Fitch.) 
Your No. 34, as I see by reference to Fitch's report, is quoted textually from that 
author, and, if my opinion be well founded, is not different from your 35, unless it be 
annectens. If there are any types to be seen, please have them sought for, and send 
me one. I have forgotten what became of Fitch's collection. (Le Conte in letter.) 
This may possibly be the insect which Dr. Fitch has regarded as the 
Tomicus pusillus of Harris. We have found the mines in abundance 
under the bark of the white pine at Providence, R. I., sometimes four 
or five occurring in the space of 6 or 7 square inches. They vary a 
good deal in irregularity, and we will select the one here figured for 
description as being one of the more regular mines. The main gallery 
is slightly sinuous, from 1J to 2 inches long, originally notched alter- 
nately on the sides, the 
notches where the eggs are 
laid being the starting point 
for the secondary galleries 
where the larvae have hatched 
and lived. About fifteen sec- 
ondary galleries arise from 
each side of the primary mine, 
the longest being about two- 
thirds as long as the primary 
gallery j all end in a slight 
enlargement in which the 
larva transforms, or connect 
with the hole through the 
bark for the exit of the insect. 
(The figure, as engraved, 
makes the main gallery and 
branches somewhat wider 
than in nature, and wider 
than in my original draw- 
ing.) The width of the main 
gallery is l£ mm ; of the secondary gallery, 1 
Fig. 248.— Mine of least white-pine bark-borer : Provi- 
dence, R. I. — Packard del. 
mm . In some cases two 
