THE CATERPILLAR. 
21 
the gum is exposed to the air, it is no longer 
gum, but silk; and the caterpillar can spin it 
fine or coarse, flat or round, just as it likes, by 
contracting or dilating the spinnaret, so as to 
make the opening larger or smaller. 
You shall hear more of the spinnaret by and 
bye, and also of the various uses the caterpillar 
makes of its thread. It is a wise and beautiful 
provision of Nature, to afford a creature so help¬ 
less, the means of constructing its dwelling, 
and sheltering itself, in some degree, from its 
enemies. And man has likewise found a treasure 
in the spinnaret, and by his ingenuity, has 
turned it to account from the earliest ages of 
the world. 
But to go on with the description of the 
caterpillar. The head is divided into two lobes, 
very rarely into three, as in the case of some 
species found in Brazil. The lobes sometimes 
end in two horns, which can be drawn in and out, 
like the horns of a snail; and they often give 
out a disagreeable odour, that is useful in driving 
away other insects, enemies to the caterpillar. 
On each side of the head are six eyes, though 
they are so small you can hardly see them without 
a microscope; and some caterpillars, when they 
have changed their skins a few times, strange to 
say, lose all appearance of eyes. 
