STATE AGRICULTURAL SOCIETY. 
469 
may be left behind when this migration occurs, being so intently 
occupied in feeding as not to notice the departure of their com¬ 
rades. But on becoming aware of their solitary situation they 
hasten after their associates ; and it is curious to observe the un¬ 
erring accuracy with which they track and find them. On com¬ 
ing to where a twig branches off, it is examined, the worm reach¬ 
ing up it a third of its own length it may be, when it ascertains 
that the brood is not upon that twig, and drawing back, it tra¬ 
vels onward, until it reaches the identical twig up which its pre¬ 
decessors have gone, and up which it at once mounts. The worm 
would seem to have some instinct by which it is informed of the 
direction in which its fellows have located themselves, or to 
possess an acuteness of smell like that for which the dog is noted, 
to be thus able to scent their footsteps. But when we come to 
examine the road they have followed, with a magnifying glass, 
we discover the clue which has doubtlessly served to guide them 
in this journey. Stretched along upon the bark we find a mul¬ 
titude of threads resembling the finest cobweb, so fine that they 
are wholly invisible to the eye. These threads the worms spin 
from tfyeir mouths wherever they go. And though so exceed¬ 
ingly slender they possess a surprising degree of strength, it be¬ 
ing sufficient to sustain the weight of the worm. Individual 
worms sometimes when they are disturbed suspend themselves 
in the air hereby. They are more apt, however, to drop them¬ 
selves to the ground. Others, when annoyed, throw their heads 
spitefully from side to side; but their most common resort, as 
already stated, is to throw the extremities of their bodies up¬ 
ward, and some will even bend themselves so far as to touch 
their heads and tails together, their bodies thus resembling a 
hoop or a ring. 
The Larva! are plump cylindrical shining worms, thinly clothed with long 
soft white hairs. When young their groundcolor 
is tawny yellow or sometimes tawny red; when ma¬ 
ture they are coal black. They have been described 
as gradually changing to a darker color with each 
change of their skin, but I think this is a mistake- 
They remain of nearly the same hue from infancy until 
the last time they change their skins, when the}' are about an inch and a quarter 
in length. It is commonly with this change of their skins that they lose their yel¬ 
low color and bocome black. When quite young and less than a quarter of 
