318 NATURAL CROSS-FERTILIZATION IN INDIA. 



one year a collection of seed from the various Districts of the Prov- 

 ince at Sibpur. He concludes his paper as follows : — 



"As regards the relationship that our three mustard oil crops 

 bear to the corresponding crops in Europe, it may be tentatively 

 held : 



(1) That rai {Brassica jimcea) is a crop not grown in Europe, 

 at any rate on a commercial scale, but that it takes the place here 

 of B. ni(jra and B. alba, which in turn are not grown in India ; 



(2) That sarson [B. Campestris var. sarson) is a crop not grown 

 largely if at all in Europe, but that in India it takes the place of 

 both B. Cairifestris, var. oleifera, and B. rafa, var. oleifera, which 

 in turn are hardly ever met with here, finally ; 



(3) That tori {B. napus, var. dichotoma) seems to be the same 

 plant as B. precox (summer-rape), or if not the same at least very 

 like and very near it, and is undoubtedly the plant that in India 

 takes the place of B. precox and of B. napus var. oleifera." 



In the genus Brassica according to Knutli,' the various spe- 

 cies are adapted for cross rather than for self-pollination. Detailed 

 observations on the fertilization of the species cultivated in India 

 do not seem to have been made up to the present. 



Indian Mustard ok Eai. 



A large number of single plant cultures of rai have been sown 

 at Piisa. The study of the various forms found in this crop in India 

 is not yet complete nor is the study of the flowers. It is hoped to 

 publish later a detailed account of the botany of the Indian oil 

 seed crops. 



Rai readily sets seed under bag and from a consideration of 

 the single plant cultures already studied at Piisa it appears that a 

 good deal of self-pollination naturally takes place. 



In 1909, 82 single plants of rai were sown at Pusa. Of these 55 

 bred true and 27 split. Seventeen plants split with regard to the 

 close or open arrangement of the pods (Fig. 3, Plate IX), while 10 

 split into tall and short plants. 



I Knuth, 1. c. 



