117 



bodies by asexual individuals. He would next allude to the other 

 mode of spontaneous generation by true virgin females. This mode 

 of reproduction had been called by the older natui-alists '' Lucina sine 

 concubita," and is now generally known as Parthenogenesis. 



Hurmeister says " that unimpregnated females lay eggs may be 

 observed in the Bombycidce if, some days after their escape from the 

 pupa case, they be impaled and allowed to die slowly. The females 

 of the SphingidcE do the same ; but never the butterflies, according 

 to Roesel's observations." 



This, of course, was known to be the case from the personal obser- 

 vation of all who had bred any of these insects. It must not be 

 supposed that these unfertilized ova as a rule produced larvse. It was 

 indeed only veiy rarely that young were disclosed. As a rule these 

 eggs were sterile, but the exception to this rule was known as 

 Parthenogenesis or the generation trom ova laid by unimpregnated 

 or virgin females. 



This mode of generation, although comparatively rare, appeared, 

 according to the observations of such unquestionable authorities as 

 De Geer, Reamur, Bonnet, Schiiicr, Jvliiller, Pallas, Ochsenheimer, 

 Roesel, and others, to be of not unfrequent occurrence. 



In the Lepidopterous (Jenus Psyche, not only the Entomologists 

 before named had observed it, but many now living could furnish 

 testimony in support of their statements. He \\ould cite instances 

 in which this mode of generation had been observed. 



The oldest communication on the subject was due to J. T. 

 Albrccht, of Hildesheim, who wrote to the Leopoldine Academy of . 

 Naturalists in 1701 a memoir, relating that he took a brown pupa, 

 which had spun itself up in a black currant bush, and preserA^ed it 

 under a glass in his summer house to sec what moth would be evolved 

 from it. At the end of July a moth of a yellowish white colour 

 escaped from it (the moth ^vas not more particularly described). The 

 moth in a few days laid a great number of eggs and then died. In 

 April of the following year, Albrecht again looked after the glass, and 

 was astonished at finding young black caterpillars in it instead of the 

 eggs. 



Another instance on record of Parthenogenesis, was one in G. 



