136 
THE BROWN-TAIL M<> I ll. 
characteristic of it. The third molt occurs during the last 
week of May (May 28-30, 1905), this usually being the 
last molt before pupation, but sometimes, as described by 
Fernald and Kirkland, a fourth molt occurs, thus making 
five stages of the caterpillar in the spring. The caterpillars 
are now usually full grown (Fig. 21), and from an inch 
Fig. 23.— Several Brown-Tail Moth cocoons on leaves. 
to an inch and a quarter long. The head is pale brown, 
mottled with darker brown. The body is dark brown or 
black, well marked with patches of orange and covered 
with numerous tubercles bearing long barbed hairs. The 
tubercles along the back and sides of the abdomen are 
thickly covered with short brown hairs in addition to the 
longer ones, which give these tubercles a velvety appearance 
under a lens. It is these short hairs (Fig. 22 at 3) which 
