EXPERIMENTS UPON THE LEPIDOPTERA. 22 7 



tioned, as were the posterior components of the preceding 

 series. The resulting moths in the successful cases were 

 fused by their heads; where the section passed a little further 

 back, the prothorax was involved. Four successful fusions 

 were obtained between cecropia and cynthia, exhibiting, how- 

 ever, no abnormal colors in any of the components. One pair 

 of cecropia was perfectly coalesced. Another pair of cynthia 

 perfectly united presents a remarkable condition of the anten- 

 nae. The left antenna of one component arises from a com- 



FIG. 4. Operation of the third category, a, united pupae, and b, united imagines 

 of S. cecropia. 



mon stem with the right antenna, that on the same side of 

 the complex, of its fellow component. The fusion is so inti- 

 mate that the basal portions of the two antennae have fused 

 for a distance of over an eighth of an inch. 



By cutting away some of the posterior segments of the 

 abdomen it is possible to produce " tail to tail " unions. Two 

 pairs of cynthia and one of cecropia were able to transform into 

 coalesced moths. Here, again, the internal relations will 

 undoubtedly present conditions of unusual interest. 



Siamese twins, united back to back, were produced in but 

 one case. The dorsal portions of the pupal abdomina were cut 

 away. A united pair of pupae is shown in Fig. 4. The result- 



