FERTILITY IN CICHORIUM INTYBUS 383 
Table I — Contiiiued 
Record for Heads Pollinated 
Fertility 
(/«) 
Total 
No. 
Heads 
With 
No 
Seed 
With 
Seed 
Seeds per Head. Remarks 
No 6.... 
9 
9 
0 
" 7.... 
10 
10 
0 
" 8.... 
13 
13 
0 
" 9.... 
12 
12 
0 
" 10. . . . 
10 
10 
0 
" II.... 
13 
0 
13 
B, B, 3 + B, 3 + B, 3 + B, 5 + B, 7, 8, 10, 
10, II, 18, 22 
0.73? 
" 12. . . . 
10 
10 
0 
" I3--- 
12 
12 
0 
" 16.... 
10 
10 
0 
" 17. . . . 
II 
II 
0 
" 18.... 
10 
10 
0 
" 19.... 
13 
13 
0 
" 20. . . . 
5 
5 
0 
possible. It is not to be considered that the degree of fertiHty is 
absolutely determined, and especially in those cases when birds (Ser. 
12, no. 11) ate all or a part of the seed produced in certain heads. 
The detailed data, however, make it quite clear that various degrees of 
self-compatibility may exist. The evidence in this particular is quite 
identical with that already reported in 1916. In Ser. 11 a compara- 
tively large proportion of plants, 5 out of 19, were self-sterile, but the 
fertility was low in each case. 
The two plants of Ser. 6 were derived from self-fertilized seed of a 
plant that was feebly self-fertile and which was the only self-fertile 
plant that appeared in my crops of this variety previous to 1916. The 
two plants were self-sterile. 
Self-Compatibilities and Incompatibilities among Plants of 
THE 1 916 Crop of Fi Generation Obtained by Crossing 
A Plant {A) of Wild Stock with Plants of the 
Variety "Red-Leaved Treviso" 
The data for the self-pollinations of this generation are presented 
in Table 2. The wild white-flowered plant A was the pollen parent 
for Series 1-4 and the seed parent of Series 5. Five different plants of 
the 1 91 5 generation of "red-leaved Treviso" were concerned in the 
parentage, as indicated in the table. The uncertainties of securing 
compatible cross-pollinations among self-sterile plants (Stout, 1916, 
