T HE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[THIRD SERIES.] 

 No. 23. NOVEMBER 1859. 



XXXIII. — On the Reproduction of the Bark-Lice (Chermes, &c.) ; 

 a further Contribution to the Knowledge of Parthenogenesis. 

 By Rudolph Leuckart*. 



[With a Plate.] 



In my small work upon the alternation of generations and par- 

 thenogenesis in Insects (Frankfort, 1858), I have proved that a 

 spontaneous evolution of the eggs takes place in the Coccina 

 and allied animals. Among the latter I particularly cited the 

 genus Chermes, which is usually referred to the Aphides by 

 entomologists, and may indeed approach most closely to those 

 animals on the whole, although in many respects it constitutes 

 the transition to the Coccina. 



What I was able to state then with regard to Chermes related, 

 however, exclusively to the wingless generation of these so- 

 called Bark-lice. I had ascertained that all the individuals of 

 this generation were of the female sex, and that they laid eggs 

 capable of evolution without the cooperation of males. The 

 winged individuals had not at that time been investigated, with 

 the exception of a few specimens of C Laricis, which were also 

 found to be virgin females. 



Hoping to be able to extend my observations to the latter 

 also, and thus to obtain an insight into the entire history of the 

 reproduction of these remarkable creatures, my statements with 

 regard to Chermes in general were rather short and aphoristic, 

 forming to a certain extent only an appendix to the observations 

 upon the Coccina and the Aphides with viviparous generations. 



As I have paid much attention to the animals in question in 

 the course of the past summer, and, in my opinion, have arrived 



* Translated from the ' Archiv fur Naturgeschichte,' 185.9, p. 209. by 

 W. S. Dallas, F.L.S., Keeper of the York Museum. 



Ann. to; Mag. X.Hist. Ser. 3. Vol. iv. 21 



