114 
flowers. 
BOTANICAL GAZETTE 
[FEBRUARY 
On such plants the lateral branches which come into 
bloom at the time when the main branch is producing normal 
Fic. 1.—Typical case of flower abor- 
tion in inne of Brassica pekinensis; about 
forty of first flowers on main axis abor- 
ted; there are five such flowers on upper- 
most lateral and none on second lateral, 
showing correlation in morph 
character according to time of blooming. 
ological - 
flowers as a rule have normal 
flowers from the first (figs. 1-3). 
This coordination between 
flowers opening simultaneously 
on different branches as to kind 
of development is very marked. 
At first view, this abortion of 
flowers appears to resemble the 
blasting of flowers which fre- 
quently occurs in all sorts of 
plants as the direct effect of un- 
favorable environmental influ- 
ences, but here the phenomenon 
is due primarily to internal 
times, some were producing 
mid-bloom and potent flowers, 
while other plants by them and 
just coming into bloom showed 
flower abortion. The abortion, 
therefore, is essentially self- 
induced. 
Flower abortion of the first 
flowers is the rule among plants 
of the varieties of B. pekinensis 
which form leafy heads and 
which are grown in the field 
under conditions which favor 
the development of heads. In 
such plants, if left to bloom, 
the flowering branches are at 
first inclosed within the head. 
At the time when the flowering branches first come to the light, 
