WARNING COLORS, WITH EXAMPLES 149 



tions occasioned by something destroying the leaves of his young 

 sassafras trees. Some of the leaves were finally found having 

 their sides brought together with silk by some insect lurking 

 inside. What was his surprise to find, on spreading them apart, 

 a quaint looking caterpillar. In a humorous mood my friend 

 brought one of these larvae to me for identification, exclaiming 

 as he came that he had found a young "hippopotamus." This 

 absurd resemblance is not greatly overdrawn so far as the 

 forward part of the caterpillar's appearance is concerned. On 

 the back are located what look like a pair of black staring eyes 

 and a broad head, which, in truth, is simply a deceptive mask 

 such as I have described in the allied tiger swallow-tail larva. 

 Another peculiar feature is added to the curious terrifying 

 markings which give to this larva a mask-like appearance. 

 This caterpillar can, like all the Papilio swallow-tails, on proper 

 occasions of alarm, thrust out an orange or reddish colored 

 scent organ at the forward end of the body, heightening the 

 effect of its resemblance to a serpent. I have seen this contriv- 

 ance especially effective in warding off birds who had the 

 temerity to peek within the shadowy entrance of the leaf serving 

 as a home for the younger caterpillars. The real head of this 

 larva is tucked away under the fore part of the bodj'. Before 

 this caterpillar is full grown the back portion of the body is 

 shiny and rounded, and colored so that it looks like bird excre- 

 ment, thus affording it protection. Various sized individuals 

 were found on the leaves of the spice bush and sassafras in 

 August. 



In this species, the last stage of the larva, which is nearly 

 two inches in length, is thickened from the third to the fifth 

 segment and the upper surface is bright green in color. Bright 

 blue spots adorn the back. On the fourth joint there are eye- 

 spots which are yellow encircled with black, and a large pupil 

 fills most of the lower portion; a line of black appears in 

 front of the segment, and a pale, pinkish spot above, 

 margined with darker pigment. On the fifth joint there are 

 also two eye-spots. Each side of the body is provided with 

 longitudinal yellow lines. Just before the transformation into 

 the pupa stage the caterpillar turns to a rich yellow ochre. 

 They are then very uneasy, sometimes migrating about to find 



