76 Fertility in Ciclioriiim intybus 



it is, the comparison may be based on the proportion of self-fertile 

 plants and their fertilities, as has been done above. 



2. Performance of families descended from crosses between the wild 

 white-flowered plant A and plant E22 of Barbe de Gapucin. 



By far the greater number of plants of the cultures were derived 

 from crosses between the two plants A and E2"2. Among the 75 J^i 

 progeny of the reciprocal crosses between these two self-sterile plants, 

 there were 8 plants self-fertile to some degree. Progenies of three of 

 these plants constituting three families, (A x E32)-i~, (A x E22)-9-, 

 and (E22 x A)-10-, have now been grown for three further genera- 

 tions. With the. one exception of series {E22 x A)-10- Ser. II. 10- all 

 the different series of these families grown in 1916 had three generations 

 of self-fertile parentage. The data for these various series will now be 

 presented together with a discussion of the results obtained for these 

 (sub) families. 



(a) The family {A x E22)-4.-. 



Data for the three series of this family grown in 1916 are presented 

 in Table II, and a summary of all the series of the family is given in 

 Table VII. 



Of the series {A x E22)-4.-3-6- only two plants were grown. These 

 were both self-sterile. The fertilities of the parental line of descent 

 were respectively 4, 13, and 5. 



The series {A x E''22)-4--S-ll- comprised 29 plants, of which 20 were 

 self-sterile and 9 self-fertile. Not only was the proportion of self-fertile 

 plants low, but the fertilities of such plants were low, ranging from 

 1 to 26% "^vit^ ^he average at 8 7o- For this series the immediate 

 parent was of rather high fertility (32 °/ J, but the ancestry previous to 

 this was of 4 and 13 °/^. The feeble self-fertility of the series as a whole 

 and of the various individuals comprising it is most noticeable, especially 

 in comparison with the behaviour of such a series as (ES x A)-4-4- 

 reported in Table I. 



Of the 16 plants of series {A x E£3)-4--0-o-, eight were self- fertile 

 with range from 2 to 62 °/^,and with an average of 25 °/^. The relative 

 number of self-fertile plants, the range of fertilities, and the average 

 fertility are all higher for this series than for (A x E22)~4--3-ll-. 



A consideration of the family history shows that there has been no 

 parent in this family with a fertility higher than 32 7o- The fertility 



