128 



AMERICAN VINES. 



soils where the hybrids were tried. This is the more readily 

 granted as the^ absolute indemnity of American vines and 



therefore of their hybrids 

 with V. Vinifera does not 

 exist, except, perhaps, for 

 the Muscadinia and Am- 

 pelosis. 



(e) Crossings and Com- 

 binations. Is it possible 

 to give precise rules help- 

 ing to forsee the results 

 sought, and to direct the 

 work of hybridization ? 

 The numerous works on 

 this subject, made on 

 different plants, by Dar- 

 win, Gartner, Wichura, 

 Decasine, Naudin, Niet- 

 ner, Nsegeli, Focke, etc., 

 have only determined the 

 general conditions of 

 hybridization and the re- 

 sults obtained, but do not 

 enable any fixed mathe- 

 matical rule to be de- 

 ducted, defining in what 

 proportion the combina- 

 tion, fusion, or juxtaposi- 

 tion of characters and 

 properties of plants united 

 in individuals resulting 

 from their crossings takes 

 place. The result of the 

 diverse combinations ob- 

 tained by hybridizing 

 vines is certainly difficult 

 to indicate 4< It is yet a very obscure subject," says Millardet, 

 " upon which we cannot throw light until many years' obser- 

 vation complete our actual experience." 



There are, however, numerous facts definitely known, which 

 may be foreseen almost with certainty, and which have been 

 discovered by Millardet. We consider it useful to rapidly 

 enumerate these, examining them from the point of view of 



Fig. 64. Nodosities and Tuberosities (a) on 

 vine roots. 



