118 Self-Incomjjatibilitt/ in HermajjJirodite Plants 



For the I^ of this line the progeny of one plant, R 9-34 No. Jfi, were 

 grown. This plant was the most highly self- compatible, and was one of 

 the best developed plants of its series. The flower heads opened 

 normally and the anthers dehisced properly. Of the 240 seed sown only 

 160 germinated. Many seedlings were poorly developed; 32 died 

 within four weeks after germination; 18 others died before the crop was 

 planted in the field. 



Of the 111 plants grown in the field only three were over 4| feet 

 tall; 60 were from 8 inches to 3 feet in height when fully mature. 

 Flower heads developed and opened poorly on nearly all plants. 



At least 50 set no seed at all, and only 6 plants produced seed in 

 considerable numbers. Giant pollen grains were found for 13 out of 30 

 plants whose pollen was examined. All plants were fasciated in some 

 degree, and in the majority the duplication was strong with much 

 torsion, but lesions were not frequent. 



The series of the /a was characterized by extreme degeneracy in 

 vegetative growth and sexual potentiality. This condition was more 

 marked in the I^ than in the /j, both as to the degree to which individual 

 plants were degenerate and as to the proportion of such plants. 



2. Families of marked vegetative vigour. No case of degeneracy 

 either in vegetative growth or in potency for seed production developed 

 in the other two lines of descent of the I^. The parents were well 

 developed plants having slight or medium degrees of fasciation. One 

 parent R 10 No. 8, shown in plate of a former paper (Stout 1917, Fig. 1), 

 was one of the tallest and most vigorous plants grown to that date. 

 The other parent {R 1^2 No. 11) was a smaller plant and bloomed for 

 a shorter period. 



All plants of both series were highly productive of seed to open 

 pollination. Some irregular or giant pollen grains were found, but these 

 were present for self-compatible and self-incompatible plants without 

 discrimination. The series 10-8- was taller in growth, and began 

 bloom later but bloomed for a longer period than did series 12-11- . 

 Each series was rather uniform in itself and the differences between 

 them were identical with those exhibited by their respective parents. 



For the I^ generation three series in each family were grown. In 

 all, there were 471 plants whose self-compatibility was determined and 

 25 others whose fertility was not studied. Every plant produced flowers 

 which appeared to be fully normal, all were highly productive of seed to 

 open pollination, and all were' of vigorous growth. 



The differences in vegetative growth of these two families seen in 



