Trouvelot.] 136 [February 27, 



jouni, without the transaction of further business, or the hear- 

 ing of scientific pa]:)ers, out of resj^ect to the memory of our 

 late member, Dr. Henry Bryant. 



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Section of Entomology. February 27, 1867. 



Mr. W. T. Brigham in the chair. Eleven members 

 present. 



The following paper was read : 



On a Method of Stimulating Union between Insects of 

 Different Species. By L. Trouvelot. 



It may be of some interest to entomologists, Avho have had no experi- 

 ence in the subject, to know how coitus can be provoked between in- 

 sects of different species, or even of different genera. It would be 

 interesting to obtain hybrids from closely allied species, and to h^cer- 

 tain if these hybrids can propagate their new type through many gen- 

 erations. I have in my cabinet a specimen given to me by Mr. Guerin 

 Meneville, which is a hybrid from the ailanthus silk worm (B. Cyn- 

 thia), and the castor oil silk worm (Bombyx arrindiu). This hybrid 

 is said to be from the twentieth generation. 



I have often obtained a union between insects of different genera; 

 of course there was too great a separation between these types to 

 obtain impregnated eggs, and as it is not very easy for one Avho has 

 no experience to unite successfully different species, I will attempt 

 to give the method which exjierience has taught me, and which has 

 always been successful. 



When the two insects to be experimented upon have been selected, 

 the female should be put in a cage, with another female of the same 

 species as the male of the experiment. Two males of the same spe- 

 cies should be kept ready. When the time arrives for males of this 

 species to seek for their mate, they should both be introduced into the 

 cage containing the two females. As this contains a female of their 

 own species, they will soon ardently seek for her. One will soon unite 

 with her. The remaining male, having no female of its own species 

 to unite with, but being excited by the sensation received from the 

 proximity of the object of his desire, will also soon unite with the 

 female of the other species, and with apparently the same ardor as 



