712 
[ Assembly 
roots of the Apple tree and their more slender, fibrous, and capillary 
branches. In the single instance in which they have come under 
my notice, the main root of the young tree was half an inch in 
diameter, half a span below the surface, at which point it was 
two-thirds surrounded by an excrescence two inches in length and 
three inches in diameter and height, and connected to the root 
by a neck much smaller than its base. (The accompanying. 
figure is a view of the back of this excre¬ 
scence, reduced to one fourth its actual 
size, and one of the small fibrous roots, 
with an excrescence thereon. The origi¬ 
nal specimen is preserved in the Entomo¬ 
logical department of the Museum of the 
State Agricultural Society.) It is of an 
t irregular, knobbed form. Its surface is 
of the same yellowish-brown color as the bark of the root, and is 
everywhere crowded with little round elevations, from the size of 
a mustard seed to that of a buck shot or a small pea. On cutting 
one of the projecting knobs, it is found to be of a very hard, 
woody texture, and without auy cavities in its center. Upon the 
maiu root, between this and the surface of the earth, was a second 
similar excrescence, but smaller; whilst upon several of the small 
capillary fibres w ere similar tubers, from the size of a pea to that 
of a bullet. 
These excrescences are doubtless formed in much the same way 
that galls and other morbid enlargements in the structure of vege¬ 
tables are produced. The parent insect insinuates herself down¬ 
wards along the side of the root, as it would appear, at the close 
of autumn, and there deposits her stock of eggs, and perishes. 
These eggs hatch when the ground becomes warm the following 
spring, and the young lice insert their beaks into the bark of the 
root to extract their nourishment therefrom. Their punctures 
produce a kind of irritation, which causes an increased flow of 
fluids to the spot where they are located. This excessive amount 
of sap thus diverted to this part occasions an increased growth of 
the wood, and results in the enormous development which we 
have witnessed. As in other cases in this family, these lice pro¬ 
bably continue to multiply without any intercourse of the sexes 
