484 



Syncotylous Races. 



other hand, the signification of the pedigree is, in this 

 case, quite different from that of the main syncotylous 

 race (p. 470). In that case we found a sudden transi- 

 tion from 19% to about 98% in the first generation, and 

 since then only fluctuation around the obtained value. In 

 this instance, however, there was a regular retrogression 

 which has reduced the mean value from 90% to about 

 50 to 55%. This value corresponds to that of an inter- 



Fig, loi. Heliantliiis anniiiis syncotyleus. i-y, fused cotyl- 

 edons, each figure of a single plant; .^f, atavistic normal 

 seed-leaf; i and 2, simple opposed syncotyls of which 

 la represents a transverse section ; 3-4, doubly folded 

 syncotyls with 3 peaks; their transverse section in 4a; 

 5. with very slight in\agination of the apex ; 6 and 7, 

 without invagmation ; 6, with one vein and 7, with two. 



mediate race without selection, especially of tricotyls. and 

 is about the same as that which was reached by the hemi- 

 syncotylous culture (p. 480). There can, however, be 

 no doubt that a further selection in the ininiis direction 

 would have reduced the proportion of syncotyls in my 

 race to a figure much below this mean. 



We thus see that after a niimis selection extending 

 over four generations, the race still contains individuals 



