102 M. E. Kegel on Parthenogenesis. 



Coelebogtjne is still in very few hands in flowering condition. 

 So far as we know, it has not been observed, from the period of 

 flowering to the ripening of the fruit, by any German botanist. 

 Observations on the so-called unfecundated seeds, such as were 

 made by Radlkofer, Klotzsch, and A. Braun, can have but a con- 

 ditional importance. That all has not been seen that may be 

 seen, in this plant, is evident from the fact that while Klotzsch 

 demonstrated, from the formation of the seed of this plant, that 

 it contained not an embryo at all, but a bud, Radlkofer and 

 A. Braun are of the opposite opinion. The latter, however, 

 made a most important observation, still unexplained by him, — 

 namely, that he found a pollen-grain with a pollen-tube on the 

 stigma of Ccelebogyne. 



In leaving Ccelebogijne on one side, since on this only those 

 are competent to speak who have been able to observe it, it may 

 be noticed that this plant has been the cause of the resuscitation 

 of the question as to the possibility of parthenogenesis in the 

 vegetable kingdom, and this the more that a similar phseno- 

 menon in the animal kingdom was simultaneously asserted by 

 von Siebold. Naudin and Decaisne in particular took up again 

 the earlier experiments on Spinacia and Cannabis, adding to 

 them a number of other plants. The result of their experiments 

 was, that female plants of Spinacia, Cannabis, Mercurialis annua, 

 and Bryonia dioica bore perfectly ripe seeds when they had been 

 sufficiently guarded against the accidental influence of the pollen 

 of male flowers. According to M. Naudin's report, neither he 

 nor M. Decaisne could discover male flowers among the female 

 flowers, which were borne in great numbers. On the other hand, 

 Ricinus communis and Ecbalium Elaterium bore no seed when all 

 the male flowers were removed before they opened. 



Naudin concluded from his observations " that only dioecious 

 plants ai-e capable of perfecting seeds without fecundation, while 

 monoecious plants jierfect their seed only under the irifluence of 

 fecundation." 



Radlkofer, from the cases made known by Naudin and Smith, 

 deduced the further law, " that ovaries which perfect their em- 

 bryos without fecundation retain their stigmas much longer in a 

 fertilizable condition than is the case when the embryo originates 

 in consequence of regular fecundation." 



As usual, the majority of naturalists have accepted these 

 statements, promulgated as certain facts. The very circumstance 

 that, in the supposed discovery, all those laws which we have 

 invariably recognized in reference to the origin of embryos are 

 opposed face to face — the attraction of the wonderful, which in 

 these days possesses a powerful charm, — has brought many over 

 to the party who believe in a parthenogenesis. 



