PIN^. BARK-BEETl ES. 



717 



upon bis neighbors, he makes an abrupt turn so as to go square across 

 one of these tracks. But this only serves to briug him into siniihir 

 proximity witli another track, and after this comes another and another ; 

 and now he reaches a fifth one, running in a different direction, requir- 

 ing another 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 iuspected, 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 seemiugly 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 Coute in letter. ) 



This may possibly be the insect which Dr. Fitch has regarded as the 

 Tomicus pusilius of Harris. We have found the mines in abundance 

 under the bark of the white pine at Providence, K. I., sometimes four 

 or fiv^e 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 1^ 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 larvte 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; 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^"""" ; of the secondary gallery, 1 



Fig. 248.— Mine of leaat white-pine bark-borer, Provi- 

 dence, R. I. — Packard del. 



™™. In some cases two 



