The Isolation of Tricotylons Intermediate Races. 425 



seedlings were counted from each lot. The result was a 

 very remarkable one. With a single exception the fig- 

 ures formed a close series of which the mean was 7%, 

 whilst the great majority of figures lay between 2 and 

 12%. (Two parents with 0.5 and 1.0 and three with 

 13, 14, and 17%.) Besides these there was a single 

 plant which stood far from the others in the series. It 

 had produced 56% tricotyls, i. e., more than half of its 

 seeds were tricotylous. For the sake of greater certainty 

 this value was determined twice. The percentage value 

 calculated from a lot of 768 seedlings was 58% ; from 

 another of 657 seedlings 54% ; with a mean of 56% for 

 1492 seedlings. 



This one plant, therefore, had a hereditary value 

 which corresponded closely with the mean value which 

 we should expect the intermediate race sought for to 

 possess. Of course the experiment was continued from 

 the seeds of this plant only. The seedlings of all the 

 other parents, tricotyls as well as dicotyls, were thrown 

 away. 



Two courses were now open to me, either simply to 

 maintain the race, or to endeavor to improve it by further 

 selection. In the former case, selection would have to 

 be avoided as much as possible, and we should have to 

 harvest and sow the seeds of all the specimens mixed 

 together, and in planting out the seedlings be careful not 

 to give preference to the tricotyls. I have not done this ; 

 but as is my custom, I have harvested and recorded the 

 seeds of each individual separately and only planted out 

 the seedlings of the best parents, that is to say the parents 

 with the highest hereditary values, for the continuation of 

 the race. 



In the summer of 1897. 37 tricotylous offspring of the 



