INTRODUCTION. 



body is clothed, when adult, with short hairs or longer 

 spines set on little pimples, or with fleshy filaments or 

 tubercles of some sort, all arranged to a greater or less 

 extent (excepting generally the short hairs) in longitudinal 

 series, but these are often not precisely aligned on the tho- 



racic and abdominal segments. 



In their earliest stage, however, before their first moult 

 and sometimes for a stage or two after it, the clothing of 

 the caterpillar is very different from what it is at maturity, 

 tlie appendages usually consisting at first of longer or 

 shorter bristles, often tubular and conveying fluids to the 

 enlarged summit, and arranged in longitudinal series differ- 

 ent from those of the spines or filaments of the mature 

 caterpillar. This earliest stage, therefore, needs special 

 attention in the study of butterflies, although the creature 

 is then exceedingly minute, and, therefore, not considered 

 in the present work. 



Certain caterpillars (and this peculiarity usually runs 

 through whole groups of allied forms), havfe certain glands 

 opening externally which may secrete fluids or odors of 

 various kinds; some of these are eversible like the Y-shaped 

 appendages on the top of the segment behind the head of 

 the Swallow-Tails and here termed "osmateria"; or the 

 lateral polypiform extrusions called " caruncles " on both 

 sides of one of the hinder segments of some of the Blues, 

 both kinds of organs being thrown out only under provo- 

 cation. 



5. The Character of the Chrysalis, 



In this state the creature is a sort of mummy, all the 

 appendages, both of head and thorax, folded over upon the 

 breast, packed closely and tightly glued, extending usually 

 to the fourth abdominal segment. In a few of the lower 

 butterflies, the tongue extends still further and is then 



