Packard.] 
INSECTS AS ARCHITECTS. 
307 
Maine I observed the female while engaged in making one 
of these singular thimble-like rolls. When about to deposit 
an egg, she picks up a leaf with her mandibles, and begins 
to cut with her jaws a slit near the base of the leaf on 
each side of the midrib, and at right angles to it, so that the 
leaf may be folded together. Before beginning to roll up 
the leaf she gnaws the stem nearly off, so that after the roll 
is made, and has dried for perhaps a day it is easily de¬ 
tached by the wind and falls to the ground. Then folding 
the leaf, she tightly rolls it up with her jaws and legs, neatly 
tucking in the ends, until a compact cylindrical solid mass 
fig. 
Fig. 237. 
Attelabus. 
Cock’s-comb gall. 
is formed. Before the roll is completed she deposits a single 
egg, rarely two, in the middle, next to the midrib, where it 
lies loose in a little cavity. While she is thus engaged, her 
partner, a little smaller, may often be seen watching her 
from the other end of the leaf, but never lending his aid, as 
in the case of the timber beetles. The roll serves as a mass 
of food for the young grub to feed upon, and may be re¬ 
garded as an artificial bud. 
The larvse of the Tiger beetles have the requisite instinct 
to make deep tubular pits in which they lie in wait for their 
19 
