242 LIFE AND HER CHILDREN. 
touched. Only the life within it, which in the first 
stage was busy storing up material in the caterpillar, 
was entirely occupied during this second stage in 
moulding that material into the future butterfly, 
which in the third stage as a perfect insect completes 
the history. 
We see then, that one of the great questions in 
all creatures which remodel their bodies must be, 
how they can keep themselves from danger in this 
second stage when they are so helpless. Some go 
through their changes quickly, and then they are 
comparatively careless of anything but to choose 
a secluded spot. Our tortoise-shell butterfly, for 
example, hangs very insecurely by the slender thread 
of her chrysalis. But then she is generally but little 
more than a fortnight or three weeks completing 
her change, and even when born in the autumn she 
becomes a butterfly before the winter, and goes to 
sleep in this form, hiding in the chinks of walls or 
palings, or in the bark of trees, till the warm spring 
comes round unless, indeed, some mild day in 
January wakes her before her time, when she gener- 
ally dies as the penalty for mistaking the season. 
But the common cabbage butterfly, if born late 
in the year, often remains as a chrysalis from Sep- 
tember to April, and would hang very unsafely 
exposed to the rough winds if merely attached by 
the tail. So the caterpillars of this butterfly, as of 
many others, bind themselves firmly to the paling or 
wall by a narrow band of silk. If you can catch 
sight of this caterpillar just when beginning its 
change, you may see it first make a little tuft of silk 
(t, Fig. 82), in which it plants its tail, and then 
