400 Tricotylous Races. 



in the fourth generation (1892) and this has been main- 

 tained since that time in spite of considerable fluctuation. 

 Up till that time my selection had been limited by the 

 fact that only hemi-tricotyls had survived to become seed- 

 parents. From this point onwards I had both hemi- 

 tricotyls and tricotyls in abundance. For the next four 

 years I selected in these two directions, and maintained 

 a tricotylous and hemi-tricotylous race simultaneously 

 (1892-1896), but as no essential difference was mani- 

 fested between the two I abandoned the hemi-tricotylous 

 race, as stated in § 2, and only went on with the tricotyl- 

 ous one. The account which follows relates solely to this. 

 But before I proceed with it I wish to call attention 

 to some facts relating to the method of culture. The seed 

 was sown in sterilized soil in pans ; the soil was not 

 manured. As soon as the cotyledons had fully unfolded 

 and before the first leaf was visible, the seedlings were 

 recorded. All, or nearly all, of the dicotylous ones were 

 destroyed and only the aberrant forms saved. Of the 

 latter I chose what I considered to be a sufficient number 

 of the strongest specimens, and planted them singly in 

 pots with heavily manured soil. The best manures for 

 this purpose are nitrogenous ones. If the number per- 

 mits it, two tricotyls are put in each pot, of which the 

 weaker is subsequently killed out. This transplantation 

 takes place in April or May ; the pots are kept under glass 

 in the garden until June, during the nights at any rate. 

 Then the plants are planted out into the bed at distances 

 of from 20 to 30 centimeters, and the larger lateral 

 branches are cut off in order that the plants may not 

 interfere with one another. The plants are monoecious, 

 the male and female flowers standing close together. 

 Self-fertilization seems to be the rule; for isolated plants 



