628 TRANSACTIONS OF THE 



Revue Horticole, Paris, September, 1855. 



UTILITY OF HYBRIDS, 



J?Y M. KLOTZSCH, OF THE ROYAL ACADEMY OF SCIENCES OF 



BERLIN. 



Translated by Henry Meigs .—{Extracts.) 

 " Camerarius, who lived in the second half of the 17th cen- 

 tury, had some notion of the crossing of plants ; but it was in 

 reality, Bradley, who, in 1739, was the first to speak of it as a posi- 

 tive fact. He says in fact that in England there were known only 

 two varieties of Auricula, the yellow and the black; that these 

 two being by chance cultivated along side of each other, experi- 

 enced the cross fecundation by means of tlie pollen caiiied by the 

 wind; they produced seeds which became the sources of all the 

 varieties having mixed colors. He reports, also, that the celebra- 

 ted gardener, rairchild,of Hoxton, fecundated a Dianthus Caryo- 

 phyllus (a clovewort), with tlie pollen of Dianthus barbatus,and 

 thus obtained the first seeds which produced the Hybrid Pinks, 

 so remarkable for their resemblance to the two plants from which 

 they proceeded. 



In 17G1, appeared the little work of Kcelreuter, soon after- 

 wards celebrated, containing his experiments on crossing plants. 

 This v/ork had, in a few years, two supplements ]3ublished. Kcel- 

 reuter had no idea of the development of the pollen, and did not 

 know, except very imperfectly, the vesicles containing the pollen j 

 but he knew that they have, ordinarily, more than one membrane, 

 and said that their envelopes had openings in them through which 

 the pollen escaped. He had no fixed notion of the mode in which 

 the pollen acts upon the pistil ; however, he had a perfect un- 

 derstanding of the two sexes and their relations. He knew, and 

 was the first to publish a crowd of methods for securing the fe- 

 cundation. He already had reason to, and he did complain that 

 many botanists were in a hurry to admit as Hybrids, a crowd of 

 plants that were not so, and so their conclusions were, of course, 

 inexact. By great pains and perseverance he succeeded in trans- 

 forming, by crossing of their pollens, JMcotiana rustica, into JYi- 

 cotiana paniculata, reciprocally. He divided hybrids into three 

 categories : hybrids perfect, or totally sterile; liybrids imperfect, 

 or feebly fertile; and lastly, hybrid varieties, which are perfectly 

 fertile. As to the cause of the sterility of hybrids, he distin- 

 guished such as are sterile on account of the imperfection of tlie 

 pollen, and those resulting from tlie imperfect state of the i^istil, 

 &c. 



