Floney-Producing Cater pillars. 133 
of the second segment, the latter being hollowed out so 
as to form for it a sheath. In the final larval stages this 
segment is elevated, transversely compressed, and inclines 
forward, thereby shielding the head as the larva moves 
about. When quiescent the neck and head are wholly 
retracted, and as the former, when fully extended, is very 
much longer than the depth of the second segment, it must 
possess considerable elasticity. 
The larva feeds on the heart of the bud, and to reach this 
cuts away the surface on one side till an opening is made 
sufficiently large to admit its head; and as it feeds the second 
segment is firmly pressed against the bud so as to permit the 
utmost elongation of the neck. Thus it is enabled to eat 
out the contents of the bud, and only desists when there 
remains but the empty shell. When so engaged the anterior 
segments are curved up and the others rest upon the stalk 
of the plant, but very small larve repose wholly in the bud. 
Not a single instance has been observed where an open 
flower has been attacked, but the destruction of buds is very 
extensive. 
But now comes the most remarkable part of the larval his- 
ory of Pseudargiolus. The whole upper part of the larva is 
covered with small, glassy, star-shaped processes, scarcely 
raised above the surrounding surface, from the centre of 
which spring short, filamentous bodies, bristling with feathery- 
looking tentacles, which the caterpillar has the power of pro- 
truding at will. It throws them out like the tentacles of 
Papilio or the horns of snails. More singular still is an 
opening upon the eleventh segment, placed transversely and 
surrounded by a raised cushion, about which the granula- 
tions that cover the body of the caterpillar are particularly 
dense. From the middle of this opening, which is shaped 
like a button-hole, issues, at the caterpillar’s will, a sort of 
transparent, hemispherical vesicle, from which is emitted a 
good-sized drop of fluid, which the animal is capable of 
reproducing when absorbed. 
