INSECT SIPPERS AND GNA WERS. 
239 
of silk, and clinging to it by his hind feet, lets him- 
self swing head downwards (Fig. 8 i). Then his head 
and shoulders begin to swell, the nervous knots within 
his body to draw together, the air-tubes to expand, 
and the skin to crack, so that by vigorous efforts he 
i-ij. 8 1. 
C, Caterpillar hanging by its t\vo cushion fret r/"at the tail, the other 
eight cushion feet are in the middle of the body. /, The six true feet ; 
b, breathing holes. D, Chrysalis breaking through the caterpillar skin. 
IS, Perfect tortoise-shell butterfly. 
can push his whole body covering back to his tail, 
where at last it drops off, leaving him hanging by 
some small hooks at the end of his body. A curious 
fellow he looks now as each part of the future butter- 
fly is dimly seen in its protecting sheath II is tiny 
