MECHANICAL FUNCTIONS. 



minute examination, may be seen to consist of the two fila- 

 ments of the tongue, or proboscis, the legs, and the antennae 

 of the butterfly. 



109. It appears, therefore, that during the chrysalis 

 state, the future organs which the butterfly requires, are in 

 the progress of perfection, as those of the chicken aie in 

 the egg, and that when the insect has remained under this 

 form a sufficient length of time for these parts to gain a 

 proper degree of consistence and strength, it then bursts 

 open the membrane, and makes its escape, as the young 

 quail does from its egg-shell. 



110. Just before the butterfly emerges from its confine- 

 ment, it is easy to see, in some chrysalids, the form of the 

 legs, antenna, and tongue, and even the color of the 

 wings. The extremities of the legs may be seen to 

 move, the wings to enlarge, and finally the whole insect 

 to struggle as if determined no longer to submit to con- 

 finement. After a few such efforts, the membrane of the 

 chrysalis gives way in a longitudinal rent down the 

 back, w r here a suture may be observed, undoubtedly for 

 this purpose. The rent then extends over the head, and 

 down the breast, and after various efforts and contor- 

 tions, the butterfly finally disengages itself entirely from 

 its covering, leaving it divided into several sections, as 

 represented by Fig. 33. But the insect, Fl - 33 - 

 though now disengaged from its prison, 



has not yet attained its full perfection, 

 for, beside being exceedingly weak, so 

 as hardly to be able to crawl, its wings 

 are folded and doubled together in such 

 a manner as to make them appear like 

 pieces of wet paper, as shown by Fig. 34. 

 The spots and markings are also indis- 

 tinct, as though their wet condition had 

 made the colors run into each other. But 

 they expand with such rapidity, that, ac- 

 cording to Swammardam, " the naked 

 eye cannot trace their unfolding, for, 

 from reaching scarce half the length of 

 the body, they acquire, O miracle of mir- 

 acles ! in the short space of about half a 

 quarter of an hour, their full extent, and 



