1144 THE BUTTERFLIES OF NEW ENGLAND. 



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 tiiat 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 gi-owth subsequent to 

 that is so great tliat 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 color and of markings has, therefore, direct relations to its 

 visibility, and it is in this later period, even more than in the earlier, that 

 we see how completely colors which are protective have established them- 

 selves. It is now that those oblique streaks upon the sides of the body are apt 

 to show themselves, which, as Lubbock has pointed out, diverge from the 

 general line of the bodv at much the same angle that the nervures of a leaf 

 part from tlie midrib. C)ften the color of these streaks is graduated into 

 the ground color iu a manner wiiicli closely resembles the shadows of a 

 raised vein upon a leaf, and it is only when we examine such objects in 

 free nature that we see how perfect the deception becomes. 



As Lubbock has pointed out, longitudinal stripes are very common mark- 

 ings and are most common and indeed almost universal upon such cater- 

 pillai's as feed upon grasses and other elongated forms of vegetation, 

 while they are comparatively rare upon such as feed upon broad leaved 

 plants. This is well exemplified by a comparison of the caterpillars of 

 our Satyrinae and Paniphilidi witli those of most Vanessidi, in the latter of 

 which, though longitudinal markings are not unknown, they are almost in- 

 variably broken up or confused with mottlings so as to loose much of their 

 force. The green color of all our Rhodoceridi and Pieridi also, notably of 

 Eurema lisa, which feed upon broad leaved plants and lie exposed upon the 

 surface beside the midrib or prominent vein, conceals them almost completely 

 from view even when tlie eye is fastened upon them. The long and 

 slender form of Anthocharis with its striking longitudinal stripes would 

 seem to render it a conspicuous object, but if seen ujDon the lank vegetation 

 upon which it grows beside the long drawn seed pods, it would hardly be 

 noticed. Caterpillars like our argynnids, which conceal themselves upon 

 the ground, are almost black and can hardly be distinguished excepting 

 when in motion. Even tlie color of the huge caterpillar of Jasoniades 

 glaucus is such an exact imitation of that of tlie leaf ujion which it rests, 

 whose sides it has so turned up that no profile view may be liad of it, tliat 

 it does not readily catch the eye. 



The few exceptions we have among our butterfly caterpillars where 

 striking and conspicuous colors obtain are perhaps not easily explained. In 

 some, doubtless, the colors ma}' be regarded as warning colors, indicating 

 the unpalatable nature of the creature, as in the case of Anosia plexippus. 

 But there are others, such as Eujjtoieta claudia and Cinclidia harrisii, 



