stout: pollinations in cichorium intybus 389 



all 10 were used as pollen-parents in a total of 50 combinations, 

 of which only 15 were fertile and these were all cases of feeble 

 fertility. There were 9 pairs of reciprocals; 5 were both sterile; 

 2 were fertile and 2 gave different results as already noted in 

 TABLE 10. 



Four of the (A X C) plants were used as pollen-parents on A ; 

 all were fertile to some degree. Nine were crossed with the 

 parent C; all but two were sterile. The four plants fertile to A 

 were sterile to C. 



The cross-compatibility within this series measured by the 

 fertility of the crosses made was decidedly feeble, both in respect 

 to the series as a whole and in respect to the individual combina- 

 tions with perhaps the exception of the cross A X {A X C) no. i. 

 No one plant, either as a seed- or a pollen-parent, was consistently 

 fertile or sterile to any considerable number of its sister plants. 

 There were no indications of impotency in any of these plants 

 and they all set considerable seed from open pollinations. 



Results of crossing {A X Ej) plants and their parents. — The Fi 

 plants derived from crossing A and Ej were crossed among 

 themselves and with their parents to the extent reported in 

 TABLE 12. Of the {A X Ej) plants four were used as seed-parents 

 with pollen of 9 sister plants in 1 7 combinations. Two were strongly 

 fertile, i was feebly fertile, and 13 were sterile. All 9 plants of 

 this series were sterile to the parent A. It may be noted that in 

 the two strongly fertile combinations the pollen-parent was no. 

 8, a plant which in self-pollination (table 3) was feebly self- 

 fertile. This plant, however, was sterile as pollen-parent with the 

 parent A. 



Two of the (Ej X A) plants were seed-parents in 14 combina- 

 tions involving sister plants. One cross was strongly fertile, i was 

 feebly fertile and 12 were sterile. Ten of the plants were tested 

 as pollen-parents with A ; of these combinations 3 were sterile and 

 7 were fertile in some degree. Seven were tested as pollen-parents 

 with Ej ; 5 were fertile and 2 were sterile. Six were used as seed- 

 parents with the pollen of Ej, and of these 2 combinations showed 

 feeble fertility. 



Both series (A X Ej) and {Ej X A) showed among themselves 

 on the whole a low degree of fertility, although 3 of the 5 indi- 

 vidual cases of fertile crosses were highly fertile. In respect to 



