APPLE-TREE CATERPILLAR TIME OF HATCHING. 187 



ning from his mouth a fine silken thread which he attaches to 

 the bark, whereby his foothold and that of those who follow him 

 is rendered more secure. On coming to a fork of the limb, they 

 halt, and there erect a kind of tent for their subsequent resi- 

 dence, by traveling around the spot, spinning their threads in 

 every direction, hereby forming a web resembling that of a spider. 

 This at first is quite slight, and wholly inadequate to shelter 

 them. Hence if a rain comes on it penetrates the web every- 

 where, and the young worms may be seen crowded together in a 

 mass, in its driest part, upon the under side of the limb. But 

 thousands of additional threads being added to it each fair day, 

 it rapidly becomes more substantial and better adapted for their 

 protection. 



The caterpillars hatch earlier or later as the season is more 

 forward or backward. Commonly the earliest clusters of eggs 

 are hatched by the twenty-fifth of April, and the latest are a 

 fortnight afterwards or even later in giving out their broods; 

 but the worms are mostly out of their shells by the first of May. 

 At this time the apple-trees are as naked as in winter, their buds 

 being merely swollen, and showing the red and green awl-like 

 points of the leaves beginning to protrude from their ends; and 

 the leaves of the garden cherry are also still inclosed within 

 their buds. The wild black cherry, however, is much earlier 

 in putting forth its foliage, its young leaves at this date and also 

 the stems which bear its flowers being half an inch in length. 

 Hence the young caterpillars which find themselves upon the 

 latter tree are most fortunate, having an ample supply of food to 

 meet their wants, whilst those upon the apple and cultivated 

 cherry are obliged to wander about, nibbling what little they 

 can reach in the ends of the buds, and probably are often much 

 pinched with hunger before the vegetation has advanced suf- 

 ficiently to enable them to feed fully. 



When they first come from the eggs these worms are less than 

 the tenth of an inch long, and about the thickness of an ordinary 

 sized pin, their bodies broadest at the head, and slightly taper- 

 ing, of a black color with pale feet and slightly clothed with 

 fine whitish hairs. At first they merely nibble a small spot 

 upon the surface of a leaf, or perforate a small hole through it, 



