PROTECTIVE COLORING 155 



sally true. Within the narrow scope of our own 

 butterflies we have many instances in which this 

 is not the case. The caterpillar of Oeneis macouni 

 is even brilliantly striped ; those of several species 

 of Papilioninae are almost black with a wliite 

 saddle, and there are many others, like Eurpnus 

 and Basilarchia, which, though having certainly a 

 green tinge, are nevertheless so obscured by other 

 colors as to have a dusky effect which is at most 

 only greenish. But the fact remains that as a 

 very general rule caterpillars of butterflies as well 

 as of moths are when hatched nearly of the color 

 of green leaves, and the various modifications which 

 we find in the mature form of our different cater- 

 pillars are gained during growth. 



This change of coloration and of markings which 

 takes place during life is oftenest assumed after 

 the second ecdysis, and, what is noteworthy, it is 

 just then that the size of the caterpillar itself 

 becomes materially enlarged. At the end of its 

 second stage the little caterpillar is rarely more 

 than two or three times as long as at birth, while 

 the rate of growth subsequent to that is so great 

 that in its mature condition it is ordinarily twenty 

 or more times as long as at birth, and its bulk 

 increases in a far greater ratio. The change of 



