INSECT ENEMIES, 111 
until it reaches the tail, forming a sort of cone, as at fig- 
ure 94, f. As the caterpillars increase in size they enlarge 
their houses upward, until the elongation makes their bags 
so large and heavy they hang to one side, instead of being 
upright, asatf. They are full grown about the end of 
July when hatched the last of May or early in June. 
The habit of the full-grown worm of letting itself down 
by its silken threads, suggested the name of Drop-worm. 
When they travel they extend the head and enough of 
the body to use three pairs of legs, each provided with a 
strong claw, while the five pairs of very short legs within 
their case retain a strong .hold with clinging hooks. 
They moult four times while growing. At each time 
they close the mouth of the sack, and retire for two days 
to cast off their skins. In closing the bag, a hole is 
always left at the end large enough to throw out their 
excrement and their cast-off skins. The body is cylin- 
drical and soft, and that portion usually concealed in the 
case is lightercolored. At maturity they fasten their bags 
securely to the twigs of the tree, instinctively avoiding 
the leaf-stalk that will fall. Then they line them with 
soft silk, and turn round, with their heads toward the 
lower orifice, where they wait to cast their skins and be- 
come chrysalids. Up to this change the sexes have been 
alike in appearance ; but henceforth they are easily dis 
tinguishable. The male chrysalis has the form of ordi- 
nary chrysalids, being about half the size of the female. 
The female chrysalis has no sign of encased wings, legs, 
and antenne, appearing asa naked, yellowish bag of eggs 
with a ring of soft light brown hair near the tail. After 
three weeks the male chrysalis works down to the end of 
his bag, and, hanging half way out, bursts his skin, and 
emerges as a moth with a black body and glossy wings, 
as at d. The male is proportionally stout bodied, with 
along abdomen, and broadly pectinated antenne. The 
female has neither wings nor legs. The bag-worm is 
