36 INHERITANCE OF SOME CHARACTERS IN WHEAT. 



4. Bearded (BBTT) x Bearded (BBTT) would give BBTT 



in both the F l5 and the F 2 . 



5. Tipped (bbTT) x Tipped (bbTT) would give the same 



bbTT in both the F. and the V . 

 Whether the above explanation, in which the bearded parent 

 contains two factors, will hold or not will be proved by the study of 

 the F 3 generation. Another explanation has been suggested by 

 von Tschermak, namely, the presence of a restraining factor in the 

 beardless parent. This, however, does not seem to fit the facts so 

 easily as that put forward by ourselves, and in this connection it 

 should be noted that the sharp distinction here drawn between 

 absolutely beardless and so-called beardless plants with short tips 

 does not seem to have been made before. It appears that tipped 

 plants have been regarded as beardless in most of the European 

 work and that crosses with really beardless plants have not been 

 made. In our Indian collection most of the ' ' beardless ' ' plants are 

 tipped and absolutely beardless plants, which are the best analysers 

 for the study of the bearded character, are rare. 



Colour of the Awns. 

 In many of the Indian wheats the awns are black, whenever 

 the wheats are fully devekmed. If, however, premature ripening 

 takes place, this colour is not developed. In one cross between a 

 black and a white awned wheat the inheritance of black awns in 

 the F 2 was determined. The black awns prevailed in the F^ and 

 in the F 2 the ratio of black awns to white was 3 "45 to 1, the actual 

 numbers being 466 black and 135 white. It was not possible to 

 separate the fully black awned plants from the intermediates, but 

 the occurrence of these two classes was evident. The parents used 

 were Punjab Type 9 (black awned), and Punjab Type 16 (white 

 awned) . 



