1922] STOUT—STERILITY 125 
the next generation of this family, the progeny of four strongly 
self-compatible plants, 275 plants were grown. Of these only 44 
were completely self-incompatible. There were, however, only 6 
plants as highly self-compatible as the immediate seed parents. 
The majority of the plants (182 in number) were feebly self- 
compatible and did not produce any viable seeds to selfing. This 
family, however, was somewhat more highly self-compatible than 
was the family derived from plant no. 1 of series 3, in the second 
generation of which only 2 plants out of 53 produced viable seeds 
to selfing. 
Selection for the highest grades of self-compatibility in B. 
chinensis was also carried through the second generation. In the 
F, generation, 26 out of 338 plants produced viable seeds to selfing. 
In the F,, 5 out of 88 plants produced such seeds. The proportion 
of self-compatible plants was low and remained about the same, 
not being appreciably increased or decreased in the second genera- 
tion. No plants classed as highly self-compatible were found in 
the F,, but this may have been due to the proportionally smaller 
number of plants grown in this generation. 
Four series comprising 86 plants were grown from seeds obtained 
by crossing certain plants of the F,. Of these, 25 were feebly self- 
compatible and one plant produced viable seeds. The F, hybrids 
between the two species exhibited the three types of sterility 
characteristic of the parent species. There was no indication of 
a general impotence of both sex organs (pistils and stamens) such 
as often results from hybridity. During the time when flowers 
opened normally, branches left to open pollination produced pods 
and viable seeds, and about roo plants of this generation grown 
in the field and left to open cross-pollination produced pods in 
abundance. 
As to mid-bloom self-compatibility, the F, hybrids were like 
the pure bred parents. Relatively few were highly self-compatible. 
In one series, derived from crossing a plant of a medium grade 
self-compatibility and one completely self-incompatible, of 50 
plants, 12 were fully self-incompatible, 14 were feebly self- 
compatible, 19 were self-compatible of medium grade, and 5 were 
