202 Mr. J. 0. Westwood's Description, ^c. 



by Mr. House, some person having leisure will follow up the 

 subject, and by a few well planned experiments still more de- 

 cidedly prove whether these hybrid productions be or be not 

 sterile, and if not in what manner the generative power is lost. 



I have only in addition to notice the singular circumstance, 

 that Smerinthus populi, one of the insects which has produced the 

 hybrid now under consideration, is likewise the species most noto- 

 rious for its hermaphroditism, A notice of the various accounts 

 recorded of the latter fact will clearly prove that the generative 

 organs of this insect (upon which in the early state of existence I 

 apprehend both hermaphroditism and hybridism are dependant) 

 are liable to great aberrations from their normal condition of 

 specific exclusiveness or unique sexuality in the individual. 



Cramer figures an hermaphrodite Smerinthus pajnili, Pap. Exot. 

 torn. iv. pi. 398, fig. A. ; as does Fischer, in the Oryctographie 

 de Moscou, pi. 11, fig. 1. The specimen was bred in 1809, and 

 desti'oyed by fire in 1812; the right side was male and the left 

 female. The entire body, " ainsi que les parties genitales," being 

 divided down the middle. 



Godart, in the Encyclop. Methodique, states, that he had found 

 two of these monstrous Sm. •populi in the neighbourhood of Paris, 

 vol. ix. p. C6. 



Dr. Klug, in the Jahrbuch der Insectenkunde, minutely describes 

 another similar specimen of the sam.e insect (vol. i. p. 257), in 

 which the right side was male and the left female. 



Curtis also describes one, presented to him by C. K. Sheridan, 

 Esq., in which the right side was also male and the left female, 

 (Brit. Ent. pi. 482) ; and Mr. Weaver reared three similar speci- 

 mens, one of which is now in the possession of Mr. Stevens, and 

 is also masculine on the right side and feminine on the left. 



Thus there are no less than nine hermaphrodite specimens of 

 Smerinthus populi on record, a much greater number than of any 

 other species ; and in all, which have been sufficiently described, 

 the male sexuality has been developed on the right side of the 

 specimen. 



