1556 THE BUTTERFLIES OF NEW ENGLAND. 



mer, and therefore is very brief. So far as I am aware, every chrysalis 

 which Hves through the winter, and whose body hangs at the merty of the 

 wind, has its head protected as I have described ; those which hang freely 

 have always the two frontal projections ; those which are also loosely girt 

 about the middle sometimes have the same, or they may have the single 

 extension in front. It is indeed, only by exception that any of our pen- 

 dant chrysalids pass the winter at all. So good an observer as Ranibur, 

 whose observations were made in Spain long ago, remarked : "Je ne con- 

 nais, du reste, aucune espece dont la chrysalide soit suspendue, qui passe 

 I'hiver en cet etat." 



It may also be noticed that chrysalids with extraordinary projections or 

 ridges in other parts of the body all belong to the same free-moving groups ; 

 the greater the danger to the chrysalis fi-om surrounding objects, the 

 greater its protection by horny tubercles and roughened callous ridges ; 

 the greater the protection possessed in other ways, 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 protuberances on the front of the head in some Pamphilidi, whicii 

 may possibly be of use in keeping the body from too great movement in the 

 cocoon-like enclosure in which the chrysalis is protected. 



There is another peculiarity in our chrysalids which strikes one as odd 

 when first noted, though it is not confined to them alone. In certain in- 

 stances the chrysalids of neighboring groups very nearly resemble each 

 other when 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 swallowtails : The chrysalids of Jasoniades and Papilio, for in- 

 stance, are very much alike, and would often be mistaken for each other 

 did the size agree ; while the caterpillars from which they came differ in the 

 most striking manner, not only in color and markings — a difference of 

 special importance in naked caterpillars — but also in form. To reverse 

 the picture, the caterpillars of Jasoniades and Eupiioeades are of precisely 

 the same form and color, on a first view differing only in some minor points 

 of markings, while their chrysalids seem made on quite a different plan. 



One finds the same thing true in certain groups if the other stages of 

 life are also examined. It only serves to show that selection has seized 

 upon every available point of structure at each stage of life, and quite inde- 

 pendently ; so that it is only by the summation of characteristics of all the 

 stages that we may arrive at a true conception of their actual relationships. 

 In some groups selection has apparently found nothing in one stage to seize 

 upon to answer its ends, and all the members of that group show then a dull 

 uniformity which would seem to indicate no great antiquity, or in other 

 words a very intimate relationsiiip between its different members ; when, 



