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LECTURE XLIV. 



TRANSMISSION AND BLENDING OF THE PATERNAL AND 

 MATERNAL PROPERTIES BY FERTILISATION'. 



(HYBRIDS.) 



As a rule the sexual union takes place between two cells which originate either 

 from the same mother-plant, or from two plants of the same kind (species or variety) ; 

 each of the two sexual cells thus transmits to the embryo properties of its own kind, 

 and it cannot be forthwith determined which of these properties the male and which 

 the female element carries into the new plant. The case is quite otherwise when the 

 fertilisation takes place between two different species of plants. In this case the male 

 reproductive cell contributes to the union different properties from the oosphere, and 

 whenever such a union is possible between sexual cells of different species, if an 

 embryo capable of development results therefrom, it must be investigated in what way 

 the various properties derived from the different parents are transmitted to the de- 

 scendants and combine with one another. It must be investigated whether any and 

 what properties in the descendant are derived from that plant which provided the male 

 fertilising element, and which of them have been transmitted to it through the female 

 cell. Experiments show that plants of different species can be successfully com- 

 bined sexually; such a union is termed Hybridisation or Bastard-formation, their 

 product being the Hybrid or Bastard; according as different varieties of a species, 



1 The first plant-hybrids were produced and carefully described by Christian Gottlieb Kölreuter. 

 He was engaged for a very long period with this subject, and this so profoundly that subsequent 

 investigators were practically unable to add anything essential. His chief work bears the title ' Vor- 

 läufige Nach?-icht von einigen das Geschlecht der Ffiaiizcn betreffenden Versuchen u>id Beobachtun- 

 gen'' (Leipzig, 1761, and continuations, 1763, 1764, and 1766). 



The most prominent of the subsequent works are : — 



William Herbert, ' Amaryllidacea;, preceded by &c., and followed by a treatise of cross-bred 

 vegetables' (London, 1837). 



Gärtner, 'Versuche und Beobachtungen über die ßastarderzeugung im Pfianzen reich ' (Stuttgart, 

 1849). _ * 



Wichura, 'Die Bastardbefruchtung im Pflanzenreich, erläutert an den Bastarden der JVeiden' 

 (2 tables in Nature-print, Breslau, 1865). 



Naegeli in ' Sitzungsber. d. kgl. bay. Ak. der ll'/ss.' (München, 1865, 15 Dec, and 1866, 

 13 Jan.). 



Charles Darwin, • Kesults 0/ Cross- and Seif J-'ertilisalion in the Vegetable A'ingdonV ^London, 

 1879). 



