AND THE MECHANIC ARTS. 



517 



bases of those projecting upward and backward. The second 

 and third thoracic segments are smooth, and unarmed, and much 

 wrinkled transversely. On the first abdominal segment is a pair 

 of long, slender horns with the distal third, smaller and bent 

 forward and outward, with the end thickened and bearing two 

 or three minute spinules, and a single long hair; this pair arises 

 from a large, black, dorsal undivided plate, while those behind 

 (on second to seventh segments) arise from a more rounded 

 black plate, divided into two half-moon-shaped pieces by a dis- 

 tinct greenish yellow space. Those of the second abdominal 

 pair are much smaller than the pair in front and those behind. 

 Those of the third abdorminal segment are not so large as the 

 first, but much longer than those behind. The pair on the 

 eighth abdominal segment are of the same size and shape as 

 those on the first abdominal segment, but are slightly shorter. 

 The suranal plate is rounded, convex, shining black, giving rise 

 to a pair of black horns shorter than the shortest ones in front. 

 Thoracic legs blackish; the middle abdominal legs of a pitchy 

 color." 



This stage lasted nine days, during which time it fed on th« 

 under side of the leaf, eating out little irregular patches. 



Following this stage a radical change occurs, the larvae as- 

 suming an entirely different aspect. The reddish-brown color 

 of the body is still retained but all of the tubercles are lost, 

 with the exception of those located on the pro-thorax. These 

 latter are much smaller than in the first stage, consisting of 

 but a pair of short, straight horns. Numbers of larvae in this 

 stage were found at Tamworth, July 20. However, most of 

 these were in badly-infested regions where the food supply was 

 limited, probably retarding their development. Great variation 

 was noted, both in the size and' color, many individuals having 

 nearly the same markings as the mature larvae, but still retain- 

 ing the horns. 



Following this stage it is almost impossible to separate the 

 larvae into definite groups, although Packard describes three 

 more distinct stages. In looking over an unlimited number of 

 specimens three general types may be found, although they 

 grade inseparably into each other. The following description 

 will apply to a large majority of healthy, full-grown larvae just 

 before the last stage is reached: 



Head, lemon yellow, a blackish-brown streak extending from 

 vertex over either eye to bases of palpi, forking just before 

 reaching mouth parts. Another spot of the same color on the 



