ON THE FORMATION OF SEEDS. 5 3 



Observations on Uie Formation of the Seeds without the aid of the Pol- 

 len ; by M. Ch. Naudin. {Communicated by Dr. B. Seemann.) 



{From 'Comptes Rendus" 1856, vol. xliii. p. 538.) 



" The sexuality of plants, now generally admitted, and the part which 

 the pollen plays in the reproduction by seeds, are most prominent points 

 in Vegetable Physiology, and there is therefore no reason to be sur- 

 prised that one of the greatest naturalists of the last century should 

 have made it the basis of a system of classification for ever celebrated. 

 To Linnaeus, and the greatest part of his followers, fecundation by 

 means of pollen was the condition sine qua non of the development of 

 the ovules and of the formation of the seeds. The law appeared abso- 

 lute and without exception, and the fine experiments of Kcelreuter on 

 Hybrids have not a little contributed to make it accepted rigorously. 

 In our own time it is carried still further : the intervention of the pol- 

 len has appeared so sovereign in the act of reproduction, that an entire 

 school, formed in Germany under the inspiration of Horkel, has not 

 hesitated to see in this agent the origin even of the embryo, attribut- 

 ing to the ovule only the secondary part of matrix or organ at once 

 protective and nutritive. This hypothesis, boldly advanced and va- 

 liantly sustained, is now almost universally abandoned, even by those 

 who have contended for it with the most talent and eclat. I have not 

 here to repeat the numberless embryological researches which, to the 

 great advantage of science, it has given rise to ; but I will add, that if 

 they could adduce incontestable cases of formation of fertile seeds with- 

 out agency of the pollen, we should still have a last argument to op- 

 pose to it, and one which would be without reply. 



Now facts exist, and they are not new ; but belief in the absolute 

 necessity of the pollen iri all possible cases of development of the ovules 

 was so fixed in the minds of naturalists, that these facts have remained 

 in the shade, and have been thought dubious, or else entirely contro- 

 verted. It appears to me that the moment is opportune to place them 

 in the proper light, and to recall to them the attention of physiolo- 

 gists. 



" If I do not deceive myself, it was Spallanzani who, about the close 

 of the last century, pointed out the first exception to the too absolute 

 law of the pollinical fecundation, by announcing that the female Hemp 

 could fructify without the agency of the male. A fact so opposed to 



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