150 Distribution of Sexes in Myrica Gale. 
small green scales corresponding in position to the “ bracteoles ” of 
the normal female dower, was found persisting, while fruits were 
developing in lower parts of the catkin. It is common to find 
rudimentary ovaries in which the “bracteoles” are replaced by a 
pair of stamens. 
Variations in Sex from year to year. 
Bushes and shoots of various types have been marked and 
examined in successive years, their previous state as regards fruit 
production being recorded. There is considerable difficulty in 
identifying an individual since the plant possesses underground 
stems. The changes recorded include only such as took place on 
the branches of single shoots traceable to the ground ; in a few 
cases where a tree or a bush is mentioned, reference is made to 
isolated tree-like plants possessing only one stem or trunk. 
In fourteen cases clumps or bushes found to be entirely 
pistillate in 1913 and in 1914, produced staminate catkins in 
1915, in some cases abundantly, and in others sparsely. One 
plant became almost entirely staminate. In some cases staminate 
shoots were produced, the upper catkins of which were herma¬ 
phrodite ; other branches bore pistillate and staminate shoots in 
about equal numbers, while a few remained for the most part 
pistillate, producing only a few staminate shoots. Thus sometimes 
the change may be generally spread over a tree or clump of bushes, 
while in others only certain shoots may be affected. In the latter 
case there may be progressive change extending over several 
seasons, since in successive years the proportion of staminate 
catkins increased. Thus certain trees and branches which pro¬ 
duced abundant fruit in 1913 developed mixed shoots in 1914, and 
in 1915 had become almost entirely staminate. In 1916, however, 
some of these showed an increase in the production of pistillate 
catkins. 
It would seem that it should be possible to gain some insight 
into the causes underlying these variations in sex, and to ascertain 
whether external conditions play any part in determining the pro¬ 
portions of the sexes which appear. The conditions which naturally 
suggest themselves are moisture, temperature, and light (with 
their influence on nutrition), and also the previous state of a plant 
as regards the production of fruit. 
Since the staminate flowers are developed early in the season 
preceding that in which they flower, while the pistillate catkins 
