Dec. 189S.1 Proceedings of the Society. 253 



are of different colors is the question whether the gonad of a certain sex and the color, 

 are both the effects of a common set of causes, or whether the color is more directly 

 dependent upon the gonad of a certain sex. As the color is produced by a chemical 

 decomposition of the hremolymph, and as the hamiolymph can hardly escape being 

 reciprocally affected chemically by the sexual organs, the second of the assumptions 

 would be indicated. 



The results so far obtained, however, do not warrant any final opinion upon this 

 subject. The pupae used were those of the common Saturnidce, Callosamia promethea, 

 Platysamia cecropia and Telea polyphemus. A cartilage knife or razor was used in 

 cutting the pupae. The two portions to be united were placed in apposition and 

 melted parafine was applied with a camel's hair brush to the edges of the common 

 wound. The cooled parafine formed a ring which kept the parts together and pre- 

 vented the escape of the haemolymph. Three groups of operations were recognized 

 according to the make-up of the complex. First, where parts from two different 

 pupae were united in normal proportions. 



Homoplastic operations upon Cynthia furnished three successful cases. Only 

 one heteroplastic union was obtained. In this specimen a part of the abdomen of a 

 female promethea was united to the rest of the body of a cynthia. The part of the 

 imago derived from the promethea showed no trace of a red color, but was buff, the 

 ground color of the cynthia. "Tandem" fusions formed the second group. In 

 these a head was cut from one pupa and a part of the abdomen of the other, the parts 

 being united on a long axis. The resulting moths possessed four pairs of wings and 

 six pairs of legs. Heteroplastic and homoplastic. 



Twin unions formed the third group. In these but little of each pupa was cut 

 off. Moths joined by the heads, by their backs or tails or sides could be produced by 

 corresponding operations. In some of the heteroplastic unions, however, was there 

 any indications of reciprocal color effects. 



In summary it was pointed out that homoplastic unions were easier to produce 

 than heteroplastic ones. Eleven per cent, of the latter was successful, while fifteen 

 per cent, of the former furnished imagines. The mortality was greatest among the 

 pupae of the first group, only six surviving the operation. The "Tandem" give a 

 percentage of success of eleven. The "Twins" furnished twenty percent, of suc- 

 cessful operations. He hoped that future operations and experiments will furnish data 

 for the solution of the problem of reciprocal color effects. After a lengthy discussion 

 the meeting adjourned. 



Meeting of February 15, 1898. 



Held at the American Museum of Natural History. 



President Dr. Love in the chair. Eight members present and several visitors. 



Mr. Davis was elected an active member. 



Mr. Beutenmiiller exhibited specimens of the curiously formed butterflies, Ar- 

 mandia lidderdalii and A. thaidina. 



Mr. Joutel showed living specimens of Ceruchns picens in decayed white birch. 

 After discussion, adjournment. 



Meeting of March. 1, 1898. 



Held at the American Museum of Natural History. 



Vice-President Groth in the chair. Twelve members present. 



