ABOUT CHRYSALIDS 237 



ades are of precisely the same form and color, on 

 a first view, differing only in some minor points of 

 markings, while their chrj^salids seem made on 

 quite a different plan. 



One finds the same thing true in certain gToups, 

 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 independently ; 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 relationship between its 

 different members ; when, if another stage be 

 studied, we find at once where selection has been 

 employing her forces, and can only regard the 

 differences here as marks of an immense lapse of 

 time since the common ancestor of all flourished 

 upon the earth. 



But to leave these general considerations and 

 to return to our chrysalids. We have pointed out 

 some common features of interest about their struc- 



