246 ALTERNATE GENERATION AND 



the shell aud the back of the auimal, where they dev<'h»p into individ- 

 uals exactly resembling the mother, aud multiiJyiug partheuogeuetically 

 on separating from her. In the fall males are boru, which cohabit with 

 the females aud produce oue or two darkly-colored winter-eggs, which 

 are surrounded by a second firm euvelope called the ephippium, to pro- 

 tect them during their hibernation. 



Although there can be no longer any doubt about the correctness of 

 these facts, which have been established by the repeated, careful, and 

 accurate observations of our most distinguished zoologists, and although 

 the existence of parthenogenesis among a number of articulate animals 

 is proved beyond dispute, attempts are not wanting to render them sus- 

 picious, and represent them as unreliable. Every truth differing from 

 long cherished opinions is received slowly and with difiQculty. 



Tigri proposed, in a paper to the Paris Academy of Sciences,* to ex- 

 plain the parthenogenesis of the Bombyx mori by the supposition that 

 there is a double cocoon containing two individuals, a male aud a female, 

 which might have copulated before leaving their shell. This supposi- 

 tion would presuppose the most extraordinary carelessness on the part 

 of the above-mentioned observers. It amounts to charging them with 

 not being able to distinguish a double from a single cocoon, or with neg- 

 lecting to examine the organs of generation aud determine the sex 

 of the individuals. Errors of so crude a nature would hardly be com- 

 mitted by men but little acquainted with methods of research, much less 

 by naturalists of high standing. 



Schaum* states that he cannot receive the theory of the iiartheuo- 

 geuesis of insects, aud thinks he can explain it away by an hypothesis 

 of Priugsheim. According to this the queen-bee, aud the workers 

 which lay eggs, might be androgynous, and possess male organs of gen- 

 eration besides their ovaries. In all cases where the skillful anatomists, 

 V. Siebold and Leuckart, dissected such bees, there were no traces of 

 testicles, so that the above supposition remains without foundation. 



The exi.steuce of hermaidirodite bees, which were observed by v. Sie- 

 bold in the apiaries of Air. Engster, of Constanz, Bavaria, | cannot be 

 brought forward as a proof against parthenogenesis, but rather seems 

 to confirm it. It was observed that the pure worker-bees drove the 

 hermai)hrodites out of the hive the moment they left their eggs, aiui did 

 not even suffer them to remain on tiie board outside. The hermaphro- 

 dites perished in a short tinu', and could never have reached the egg- 

 laying stage, even if eggs had afterward formed in their originally 

 empty ovaries. According to Pringsheim, every queen would have to 

 be an hermaphrodite; but in the lance-winged and drone-producing 

 queens, which were repeatedly examined by the above observers, no 

 trace of androgynism or of spermatozoa could be found. 



* Couipt. Rend., Iv, 1862, p. lOG. 

 t Borliuer Entoin. Zeitscbiift, viii, p. 93. 



X C. Th. V. Siebold oa Androgynous Boos, Zeitschrift fiirw«\'issenscliaftliclie Zoologio, 

 vol. xiv, No. 1, and in the Eichstiidter Bicuenzeitung, year xix, p. 223. 



