THE CYCLE OF LIFE 



21 



thrust into the silken cushion,, and there before our 

 eyes the characteristic colors of the chrysalis appear, 

 at first green, in some cases remaining so throughout 

 pupation, in others turn- 

 ing a protective wood- 

 brown with a dash of 

 frosty-white here and 

 there. 



This June generation 

 has all experienced the 

 wonderful transition be- 

 fore the month's end. 

 Each is encased in a 

 hard brown shell, a cov- 

 ering admirably adapted 

 for the changes which 

 occur during this quies- 

 cent period. This shell 

 is protected at every 

 point of probable contact 

 by callous projections. 

 Capable of no external 

 million, the pupa lies in a trance, as it were, for from 

 ten to twenty days, according to the character of the 

 weather, warm weather favoring growth. 



/ r^ o 



When it is known, however, that the being enters 

 this tenement as a caterpillar and conies forth by-and-by 

 a bright butterfly, it is evident that great activity has 

 existed within this shell. The hour when we are to 

 see the butterfly is foretold by a duller color, the line 

 markings become less distinct, the shell appears to be- 



FIG. '22. Brown pupa-case or chrysalis 

 of black swallowtail. Enlarged. Photo- 

 graphed from life. 



