EXPERIMENTS UPON THE LEPIDOPTERA. 223 



Better success was attained in joining an anterior end of 

 one pupa to a posterior end of another. Here the section was 

 made completely across the body just back of the posterior ends 

 of the wing cases. Altogether, sixty-one operations of this 

 kind were performed, affording but four living imagines. A 

 compound pupa of this kind is shown in Fig. i, a. Both parts 

 were from cynthia pupae. Three out of twenty-one cynthia 



* 



FIG. i. Operation of the first category, a, compound pupa; b, compound moth of 

 P. cynthia. 



cases furnished moths, two of them emerging unassisted and 

 expanding their wings. One of these is also shown in Fig. i, b. 

 To a casual observer this specimen would appear quite normal. 

 The differences in general color and pattern between the ante- 

 rior and posterior parts of the abdomen are so slight as to be 

 easily overlooked. A rather curious condition appears in the 

 specimen. The posterior part of the abdomen was taken from 

 a male pupa, while the rest of the body was that of a female. 

 The result is that the eggs contained in the female portion 

 were too large to pass out through the male passages, and a 



