AND THE LOWER ANIMALS. 255 



respect to the anatomical facts ; it is the same 

 with those of the physiological kind. It is only 

 necessary to recall those animals which produce 

 either males or females, according as the male 

 parent has had any share in the process or not 

 (bees), and especially those which deposit simulta- 

 neously ova capable of being developed, and others 

 which perish if they have not been previously fer- 

 tilized (silkworms). 



There is at present nothing to warrant the suppo- 

 sition that in these animals the reproductive bodies 

 have a different primitive constitution ; and as some 

 are unquestionably ova, it ought to be the same with 

 the others.* 



Notwithstanding my reservations, parthenogenesis 

 is still to my mind a constant phenomenon. With 

 my confreres, I believe that there exist true females 

 which deposit genuine ova that are developed with- 

 out any intervention on the part of the male. But I 

 believe that this phenomenon is far less frequent than 

 has been supposed. 



Meanwhile it remains to be accounted for. 



But is it possible? Is the cause of these phe- 

 nomena to be found in the fecundating action of the 

 older writers, in Owen's spermatic force, or in herma- 

 phroditism of the ova as supposed by Barthelemy ? 

 These hypotheses are all gratuitous. They all lead us 

 far from direct observation. Let us therefore leave 



* To these purely theoretical reasons I may add that Leuckart's 

 figure of the ovary of Solenobia lichenella seems to prove that this 

 species, in which both he and Siebold demonstrated the existence 

 of parthenogenesis, produces true ova, which are marked in the 

 commencement by the presence of the germinal vesicle and spot. 



