376 A. B. STOUT 



the offspring of A and Ej, four were self-fertile. Seventeen plants, 

 the offspring of C and Ej, were self-sterile, as were 30 plants from seed 

 of a cross between a white-flowered plant, {A XC) no. i, of wild stock 

 and a plant of the variety "improved striped-leaf." The number of 

 self-fertile plants, therefore, varied greatly in the different series, but 

 in no series was the proportion very large. 



The self-fertile plants mentioned above appeared after only one 

 generation of ancestry known to be self-sterile. Furthermore, the 

 parents in each cross were not closely related and were somewhat dif- 

 ferent in vegetative habit and flower color. As previously recognized 

 (1916, p. 415), these results raised some question regarding the in- 

 fluence of wide-crossing as compared with that of inbreeding on the 

 development of self-compatibilities, especially as continued inbreeding 

 in the variety "red-leaved Treviso" had in two generations given only 

 one feebly self-fertile plant out of a total of 49 plants (complete data 

 given in 19 16, Table 7). 



In order to obtain further data on this question, it was planned to 

 continue inbreeding within this variety, increasing the number of 

 plants grown in 1916, and at the same time to grow for comparison 

 an Fi generation from crosses between plants of this variety and a 

 self-sterile plant of a wild stock. The present paper will deal especially 

 with the data obtained from these cultures. 



Description of the Cultures 



The variety " red-leaved Treviso" is a cultivated salad chicory that 

 has been developed in continental Europe. As grown for commercial 

 seed production the variety is biennial, seed being sown one summer 

 for a crop that matures in the following summer. As grown in my 

 culture the plants are more nearly annual. Seed is sown in January 

 in fiats, and the seedlings are potted and kept in continuous growth 

 in the greenhouse until spring, when they are planted in the field. 

 Under such treatment the plants, as a rule, reach full development in 

 the following August. The general habit of growth of the mature 

 plants is well shown in text-figure i. The height has ranged from 4^/2 

 to 63^ feet with the greater number of plants about 5 feet tall. The 

 plants are rather sparsely branched near the base but rather abundantly 

 branched above. In the early stages of growth the rosette leaves are 

 numerous, of large size, and erect. One of the marked characteristics 

 of the family I have grown is the development of a type of fasciation 



