Tricotyloiis Races Do Not Arise by Selection. 401 



set as much seed as those grown in groups. The seeds 

 do not fall out and as soon as the desired quantity is ripe 

 the whole raceme is cut off and rubbed between the hands. 

 One cubic centimeter per plant, and often less, is suffi- 

 cient for next year's seed ; as a rule I obtained about 

 4 to 5 cubic centimeters from each individual. 



After the transplantation of the seedlings the length 

 of the cotyledons, and of their stalks especially, increases 

 considerably. In this way it may happen that specimens 

 which, at their first examination, appeared to be pure 

 tricotyls are found to have two of their cotyledons united 

 at the base, and therefore to be deeply cleft hemi-tricotyls. 

 I have as a rule removed such specimens when I discov- 

 ered them, and not cultivated them further, although this 

 is not actually necessary. 



In the summer of 1892 I had 11 tricotylous speci- 

 mens which flowered in a group as far removed as pos- 

 sible from the hemi-tricotylous culture already men- 

 tioned. The harvest gave a maximum of 11.9% tricotyls, 

 but on the average only 1 to 6.5% with a mean of 3.5%. 

 In 1893 I planted out the purely tricotylous seedlings only 

 of a seed-parent with a hereditary value of 6.3%. I saved 

 the seeds of 15 plants, examined between 500 and 1000 

 seedlings per seed-parent, and obtained values which fluc- 

 tuated between 2.6% and 7.4%; mean 4.7% (1894). 

 I selected the parent with 7.4% for the continuation of 

 the race and only planted out the best tricotylous speci- 

 mens from amongst its offspring. I had 44 tricotyls 

 amongst 1000 seedlings to choose from; besides these 

 tliere were 31 hemi-tricotyls and one tetracotyl. I re- 

 peated the evaluation of the ratio with 4000 seedlings and 

 found 7.2%, that is to say, about the same value. 



At the end of the summer of 1894 my culture con- 



