390 BOTANICAL GAZETTE [JUNE 
the entire plant had been removed from alternating conditions (except 
those of day and night) for nearly two months, and the sori were borne 
on proliferations produced while the plant was in the laboratory, 
consequently on parts of the thallus whch had never been subjected to 
alternating conditions. This result*is similar to one obtained by 
WILL1aMs (5, p. 547), but goes one step farther in showing that the 
periodicity is transmitted to new structures formed from the original 
plant, even when these are not subjected to alternating conditions. 
These proliferations were, of course, produced by the protoplasm of 
the parent plant; it still remains to be seen whether the periodic habit 
can be transmitted through the protoplasm of the egg 
A few observations were made at Beaufort in the summer of 1905, 
but no satisfactory records were obtained. The observations made, 
however, indicate that the behavior of the sexual plants was like that 
observed during the past summer. 
Many specimens of several species of Dictyota have been obtained 
from two localities in Jamaica. Among these are four sexual plants— 
two male and two female—collected by the author at Port Antonio, 
April 13, 1906, and eight sexual plants—two male and six female— 
collected by Mr. I. F. Lewis at Port Morant, July 16,1906. Although 
this material is too scanty to warrant a conclusion, it is interesting to 
note the direction in which the evidence points. 
The specimens from Port Antonio have all the sori i of about the 
same age, and at the same stage of development that would be expected 
for plants of Dictyota at Beaufort, N. C., on the same day. In the 
specimens from Port Morant, the male plants have all the sori of the 
same age, while all the female plants have sori of two ages, one set 
being mature, and the other being young and at a stage corresponding 
to that of the antheridial sori on the male plants. These sori of two 
ages probably represent two crops of eggs, the older of which was not 
shed before the younger one was produced. The age of the older 
crop cannot be stated with certainty, but the age of the younger crop 
of eggs and of the antheridial sori does not agree with the age of sori 
on plants collected by the author on the same day at Beaufort. They 
seem at about the stage of development, however, that would be 
expected for Dictyota at Bangor on this day. These facts indicate 
that, on the coast of Jamaica also, Dictyota shows periodicity in the 
production of sexual cells. As there are practically no tides on this 
