20 CHANGE OF SKINS. 
three, four, and four more, that makes 
eight, in one inch, mamma. 
Mother, Therefore, as eight are con- 
tained in the inch, each division is one 
eighth part of an inch. The caterpillar is 
about one eighth of an inch long ; but it 
rapidly increases ; and in a few days it 
throws off its first skin. 
Lucy, You told me before, that they 
change their skins several times ; and I 
have since been thinking how they manage 
when the old skin is gone and the new one 
not quite grown. 
Mother, They are never in such an 
uncomfortable state ; for at their very birth 
they are provided with all the skins in 
which they are afterwards to appear. 
When the outer skin is, from the growth 
of the animal, become too tight, the 
creature seems to lose its appetite, and to 
be sick ; after a day or two, this skin 
bursts along the back, and the caterpillar, 
first disengaging its head and legs, then 
creeps out of its old dress, and appears in 
its new one. 
