236 A BUDGET OF CURIOUS FACTS 



as by firm swathing or a safe retreat, the smoother 

 the surface of the body and the more regular and 

 rounded its contours. We have thus a complete 

 explanation of all the angularities in the surface 

 of the body, with the sole exception of certain 

 horn-like j^rotuberances on the front of the head 

 in some Pamphilini, which may jjossibly be of use 

 in keeping the body from too great movement in 

 the cocoon-like inclosure in which the chrysalis is 

 protected. 



There is a further peculiarity in our chrysalids 

 which strikes one as odd when first noted, though 

 it is not confined to them alone. In certain 

 instances the chrysalids of neighboring groups very 

 nearly resemble each other, while the caterpillars 

 from which they came differ strikingly ; and the 

 reverse is equally true. No better instances can be 

 given than in our genera of swallow-tails. The 

 chrysalids of Jasoniades and Papilio, for instance, 

 are very much alike, and would often be mistaken 

 for each other did the size agTee ; while the cater- 

 pillars from which they come differ in the most 

 striking manner, not only in color and markings 

 — a difference of special importance in naked cater- 

 pillars — but also in form. To reverse the pic- 

 ture, the caterpillars of Jasoniades and Euphoe- 



