84 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
snows of winter it would remain sufficiently moist for the existence of 
the insect, which completes its transformation within. 
Mr. 0. A. Walker has brought us the insect in its different stages cut 
out of oak branches, which occurred in abundance at Chelsea, Mass. 
Late in August, 1888, this borer was reported to be especially abundant 
in Warwick, R. I., so that the ground was said to be strewn with the 
smaller branches of oak and locust trees. We arc indebted to Dr. Fitch 
for the most detailed information regarding this curious longicorn : 
The severed limbs are usually but eighteen inches or two feet in length, but Pro- 
fesfiOT Peek States thai limbs an inch in thickness and live feet in length are sometimes 
found. I have seen a limb cut off by this insect which was ten feet in length and an 
inch and a tenth in thickness, and have repeatedly met with them seven and eight 
feet long and usually an inch, but in one instance an inch and a quarter, in thickness. 
The parent beetle seems aware that her progeny in their infancy will be too feeble 
to masticate the hard woody fibers of the limb. She, therefore, selects one of the 
small twigs which branch off from it, which is not thicker than a goose quill, with its 
base composed of soft wood, the growth of the last year, all the remainder of the twig 
being the green succulent growth of the present year. She places her egg near the 
tip of this twig, in the angle where one of the leaf-stalks branches off from it. The 
young worm which hatches therefrom sinks himself into the center of the twig and 
feeds upon the soft pulpy tissue around him until it is all consumed, leaving only the 
green outer bark, which is so thin and tender that it withers and dries up, and ere 
long becomes broken. By the time this green tender end of the twig is consumed the 
worm has acquired sufficient size and strength to attack the more solid woody portion 
forming its lower end. He accordingly eats his way downward in the center of the 
twig, consuming the pith, to its base, and onward into the main limb from which this 
twig grows, extending his burrow obliquely downward to the center of the limb, to a 
distance of half an inch or an inch below the point where the lateral twig is given off. 
The worm, being about half grown, is now ready to cut the limb asunder. But this 
is a most nice and critical operation, requiring much skill and calculation ; for the 
limb must not break and fall while he is in the act of gnawing it apart, or he will be 
crushed by being at the point where it bends and tears asunder, or will fall from the 
cavity there when it breaks open and separates. To avoid such casualties, therefore, 
he must after severing it have time to withdraw himself back into his hole in the 
limb and plug the opening behind him before the limb breaks and falls. And this 
little creature accordingly appears to be so much of a philosopher as to understand 
the force of the winds and their action upon the limbs of the tree, so that he can bring 
them into his service. He accordingly severs the limb so far that it will remain in 
its position until a strong gust of wind strikes it, whereupon it will break off and fall. 
But the most astonishing part of this feat remains to be noticed. The limb which 
he cuts off is sometimes only a foot in length aud is consequently quite light; some- 
times ten feet long, loaded with leaves, aud very heavy. A man by carefully inspect- 
ing the length of the limb, the size of its branches, aud the amount of foliage growing 
upon them could judge how far it should be severed to insure its being afterwards 
broken by the winds. But this worm is imprisoned in a dark cell only an inch or two 
long in the interior of the limb. How is it possible for this creature, therefore, to 
know the length and weight of the limb and how far it should be cut asunder ? A man, 
moreover, on cutting a number of limbs of different leugths so far that they will be 
brokeu by the winds, will find that he has often miscalculated, and that several of the 
limbs do not break off as he designed they should. This little worm, however, never 
makes a mistake of this kind. If the limb be short it severs all the woody fibers, 
leaving it hanging only by the outer bark. If it be longer a few of the woody fibers 
on its upper side are left uncut in addition to the bark. If it be very long and heavy 
