28 Herr N. Datnia on Parthenogenesis in Spiders, 



shaped web which it spins, after the manner of Segestria and 

 Amaurobius, at the entrance to its abode. It is abundantly 

 represented in ray collection ; but what has struck me very 

 forcibly in this connexion is the fact that there is not a single 

 male among my specimens, and that I have never yet met 

 with a male, either alive or dead : I do not know the male at 

 all. Does not this very absence of the male constitute an 

 indirect testimony in favour of the parthenogenesis of 

 Filistata ? 



It may here be remarked, further, that neither Thorell, in 

 his two memoirs *, nor C. Koch f says anything about a male 

 of Filistata iesiacea. In response to my inquiries I learn 

 from the well-known arachnologists Dr. C. Chyzer, of Ujhely, 

 and Prof. W. Kulcynski, of Cracow, that, with the exception 

 of a single male received by the latter from Madeira, they, too, 

 have not met with a male specimen of Filistata. It is, how- 

 ever, not my intention to imply that males of Filistata never 

 occur; I would merely remind the reader of the males of 

 Psyche helix, so long missing, and first discovered by C. Glaus. 

 It is, indeed, well known that among other creatures also, 

 especially insects, where parthenogenesis is met with, tlie 

 males, at least at one period, are rare or entirely wanting. 



It is self-evident that further observation is still necessary 

 in order to prove whether parthenogenesis in Filistata is 

 accidental, as, for instance, in the case of Bombyx mori and 

 certain butterflies, or actually a phenomenon of regular 

 occurrence, as in Psyche, Solenohia, &c. Moreover, it is 

 reserved for subsequent investigations to decide whether 

 parthenogenesis does not occur in other spiders also. 



Another noteworthy point may be alluded to. We are 

 aware that it is not until they have undergone their last 

 ecdysis that spiders are mature or capable of reproduction. 

 After copulation or the first deposition of eggs, as the case 

 may be, spiders change their skin no more. 



It was quite contrary to my expectation therefore when 

 the parthenogenetic female that I have been observing 

 moulted on the 29th of September of last year, consequently 

 two months after it had spun its virgin cocoon. This led me 

 to the following reflection : either a kind of paidogenesis 

 occurs in Filistata — that is, parthenogenesis is here relegated 

 to a stage in life at which sexual reproduction does not other- 

 wise take place, as we meet with it in the case of midges, 

 and in this event it is possible that differences from the fully 



* T. Thorell, ' On European Spiders ; ' ' Remarks on Synonyms.' 

 t C. L. Koch, ' Die Arachniden,' i.-xviii. (Niirnberg). 



