Brassica Crosses. 5 



White-fleshed Turnip on White-fleshed Round Swede. 



White-fleshed Turnip on Asparagus Kale. 



White-fleshed Turnip on White-fleshed Swede. 



White-fleshed Turnip on Yellow-fleshed Turnip. 



White-fleshed Turnip on Yellow-fleshed Swede. 



Yellow-fleshed Turnip on Colza Rape. 



Yellow-fleshed Turnip on Ragged Jack Kale. 



Yellow-fleshed Turnip on Yellow-fleshed Swede. 



Yellow-fleshed Turnip on White-fleshed Swede. 



Yellow-fleshed Turnip on White-fleshed Turnip. 



Asparagus Kale on Yellow-fleshed Tankard Swede. 



Ragged Jack Kale on Yellow-fleshed Tankard Swede. 



Yellow-fleshed Round Swede on Ragged Jack Kale. 



From all these crosses hybrid plants were obtained, many of which proved 

 sterile, while others unfortunately died off in the winter before the question of 

 their fertility or sterility could be ascertained. 



The most interesting of these are shown in figs. 28 to 57 (Pis. 4 to 6). 



Group III. In this series of crosses abundant seed was produced, and plants 

 of the F 1 and F 2 generation were easily raised. 



The seeds from the F 1 generation were sown and about 200 plants from them 

 were grown for observation. In the second filial generation (F 2) segregation 

 occurred in all cases. 



In order to obtain an impartial estimate of the numbers and characters of the 

 plants, neither Professor Percival nor myself had anything to do with the classifica- 

 tion of the segregated plants, this being left to the judgment of one of our assistants 

 who had no inclination to look for Mendelian numbers. Many of the results, as 

 will be seen below, are confirmatory of Mendel's laws. Where the figures appear 

 to disagree with the well-known ratios among segregated plants of the F 2 genera- 

 tion, it is possible that the discrepancy may be due to the great difficulty in deciding 

 into which group individual plants should be placed. 



c? ? 



Ragged Jack Kale on White Swede. 



Ragged Jack Kale (PL 7, fig. 58) is a form of Brassica which in general habit and 

 flower resembles a Colza Rape but the leaves are laciniate. The Swede used for 

 the female parent was a white-fleshed variety with purple top (fig. 59). 



The plants of F 1 had strong Swede-like leaves ; they were, however, slightly 

 more incised at the margins than the normal Swede parent, indicating the influence 

 of the Ragged Jack parent. The rootstock was thick with little tendency to 

 " bulbing " (fig. 60). 



The plants of the F 2 generation, of which 198 were grown, were of several forms. 

 There were bulbing and non-bulbing plants, some having leaves like the Swede, 

 others the laciniate form of the Ragged Jack Kale. 



The following were the classes into which the plants of this generation were 

 divided, together with numbers belonging to each class. 



