INSECT SIPPERS AND GNA WERS. 
237 
out little yellowish-grey caterpillars, and these give 
out at once a fine silken thread from their under lip 
and spin a slight web over a leaf. This done, they 
crawl away in company and travel from leaf to leaf, 
feeding busily all day but always returning to their 
silken tent at night. They have no thought beyond 
eating as they move along on their ten cushion feet, 
two at the tail and four under the abdomen {cf y Figs. 
80 and 81), which are not true feet at all but foldings 
in the skin, each bearing a circle of spines which 
Fig. 80. 
b, Butterfly's head ; t y the trunk ; c e, compound eyes ; c, caterpillar's 
head; a a, antennae ; m m, mandibles; p p, palpi of the jaws; sp, 
spinning - tube ; cf, cushion -foot seen from underneath, showing the 
circlet of spines ; e, egg of the tortoise-shell butterfly. The true size 
is about that of a rape seed. 
help it to cling to the twigs. Their six real jointed 
feet (f 9 Fig. 81, p. 239) near the head, they use 
both for walking and for grasping the leaf, while 
they cut it with their horny mandibles or outer jaws 
(m y Fig. 80), which work horizontally between their 
lips, and then pass the pieces on to be chewed by the 
real jaws within, whose palpi or feelers are seen at p. 
Thus they " feed and feed alway," guided probably 
chiefly by touch and taste, though they have tiny 
