ImprovciJiciil of a llcim-Syncotyloiis Race. 47[) 



tion and the planting otit of hemi-syncotylous seedlings 

 suddenly increased the i)roportion of the latter and cor- 

 res])ondingly diminished that of the syncotyls ; hut only 

 for a time. In the harvest of 1891 hoth have hecome 

 low, and from that time onwards selection has gradually 

 increased, with but slight de\iations, both the number 

 of hemi-syncotyls and that of syncotyls. In the last 

 harvest ( 1896) the numbers are given for the plant with 

 the largest proportion of hemi-syncotyls. The average 

 number of the hemi-syncotyls of the whole crop was, 

 however, 29%, and that of the syncotyls 31%. 



The result of this experiment of seven years was, 

 therefore, that by the double selection of seed-parents, 

 which produced the largest number of hemi-syncotyls, 

 and of hemi-syncotylous individuals f(^r seed-])arents, 

 we do not even a]3proach a pure hemi-syncotylous race. 

 In spite of the inevitable fluctuation of the numbers, the 

 syncotyls remain in about the same proportion as the 

 half type. If we think how many degrees of sym])hysis 

 this latter embraces as opposed to the uniform group of 

 the true syncotyls, the number of the latter actually found 

 assumes even greater importance. 



In the pedigree on page 480 I have gi\en a summary 

 of the whole course of this culture. In this I have en- 

 tered only the totals of hemi-syncotyls and syncotyls: but 

 as half of these values belonged to hemi-syncotyls, the 

 pedigree would not have been different if these alone 

 had been entered, except of course that the percentage 

 figures at the top of the table would have to be halved. 

 As usual, these figures relate to means of small groups, 

 which in this case embrace values between 1 and 9, 10 

 and 19, 30 and 39, etc. The figures which arc given for 

 the se\-eral generatit^ns indicate the number of indixidnals 



