Plants, and Parthenogenesis. 89 



to which he thereupon attributes, without further research, a 

 parthenogenetic mode of reproduction. 



That the investigations, repeated by Naudin, of the develop- 

 ment of unfertilized ovules in Cannabis and Mercurialis, and 

 likewise the older experiments by Spallanzani, Lecoq, and others, 

 asserting the same development to occur in the ovules of Spi- 

 nacia, are untrustworthy, follows as a consequence of the re- 

 searches undertaken by Regel and Schenk. On the one hand, 

 Regel always detected male among the female flowers on the 

 same plant ; on the other, it follows (in accordance with the 

 rule) from Schenk's admirable experiments, that the notion of 

 the formation of fertile seeds without the operation of pollen 

 upon the ovules of a plant, is not established. Both observers 

 concur in saying that, of all the plants adduced as partheno- 

 genetic, the Ccelebogyne, which was not accessible to them for 

 investigation, forms the only exception to the general law, and 

 that ovules become fertile seeds only after the act of fertilization. 

 Schenk was led to believe in the existence of the exception 

 mentioned, inasmuch as he relied upon the authority of Braun, 

 who made it appear that he had for a long time examined the 

 Ccelebogyne with the most scrupulous care in his room ; but 

 Regel formed a more unbiassed opinion, and gave to the unsup- 

 ported statements of Braun and Radlkofer no such implicit belief. 



Both these careful observers would have convinced themselves 

 with ease of the groundlessness of the hypothesis of Radlkofer 

 and Braun, if they had been enabled to examine a plant of 

 Ccelebogyne in bloom. 



The delusion of the two last-named observers, that they were 

 able to make out, from among the structures of the normally- 

 formed male flowers, the impossibility of the presence of a her- 

 maphrodite flower in Ccelebogyne, rendered them blind to the 

 existence of the comparatively large anthers, which, in fact, are 

 often developed at the base of the calyx of the female flowers, as 

 I have had opportunities of observing for two years in the spe- 

 cimens growing in the Berlin Botanic Garden. 



That Radlkofer did not discover the hermaphrodite flowers of 

 Ccelebogyne is attributable to the hasty character of his observa- 

 tions during his travels; but this, if in the least explicatory of 

 the circumstance, is no apology for it. The finding of pollen on 

 the stigma ought to have rendered him cautious, had he been 

 only anxious for the discovery of the truth, and not, as is clearly 

 the case, for the promotion of a literary work by the fallacious 

 evidence of a preconceived interpretation. But that Braun, after 

 several years' observation of the plant in question *, and after 



* Whilst this sheet was passing through the press, T received from Prof. 

 Braun his just-published " Supplement to the Treatise on Parthenogenesis 



