<;. p. HECTOR. t) 



progress with the object of verifying this and also of determinino- 

 the mode of inheritance of certain other characteis. 



In addition to the examples described above of undoubted 

 splitting crosses, stray variant plants have also been found in 

 twelve of the 1912 pure line plots started from single plants 

 selected in 1910, and in fifteen of the 1912 Dinajpur series started 

 from single plants selected in 1911, amounting to about fifty in 

 all. Some of these may prove to be accidental mixtures but 

 some cannot be matched with any of our other types, and have 

 all the appearance of being the F^ generation of crosses which 

 must have taken place within our area in 1911. Seed of all these 

 is being preserved and will be sown in 1913 and the results noted. 

 From the above cases there is reason to believe that natural 

 crossing in rice is more common than was at first supposed. 

 Moreover, under the conditions in which rice is grown by the 

 cultivator, whose varieties are never free from mixtures, it would 

 probably take place to a considerably greater extent than in our 

 area at Dacca. Even if it did not occur to any greater extent 

 than the cases cited would indicate, it would be quite sufficient 

 to account for the extraordinarily large number of types which are 

 to be found, when one takes into consideration the extent and 

 great antiquity of the cultivation. Certain facts also which have 

 been brought to our notice lend further evidence to this belief. 

 For example, a cultivator from the neighbourhood of Chandpur 

 recently informed us that on his own land within the past twelve 

 years the number of distinct types to be found in his fields has 

 increased from eight or ten to almost a hundred, although he has 

 imported no new varieties. 



The main conclusions to be drawn from the above results 

 are : — 



1. That in Lower Bengal under favourable conditions cross- 

 fertilisation may take place in rice to an extent which may be 

 provisionalh^ estimated at about 4 per cent. 



2. That this cross-fertilisation takes place wholl}' through the 

 agency of the wind and would seem to be effective only between 

 flowers of adjacent plants to a radius of a few feet. 



