122 BOTANICAL GAZETTE [AUGUST 
investment of the smaller nucleus. He speaks of “‘male nuclei’’ 
and not of male cells. His figure shows two nuclei in a common 
cytoplasmic mass. STRASBURGER (4) and JAGER (6) both recog- 
nized two “cells.” Miss RoBERTSON (18) figures the division of 
the body cell, but no cell plate is shown on the spindle, even in the 
late telophase; while her figure of the completed division lacks 
clearness on this point, owing to a possible inaccuracy in drawing 
or in technique. In her discussion she speaks of a “functional 
male nucleus” and “‘inequality of the sperm nuclei.” 
By the time the two male cells are formed, the vacuolization 
along the margin of the larger cell has become quite pronounced | 
(fig. 26), and this continues until finally the cytoplasm has prac- 
tically all withdrawn from the plasma membrane and collected 
about the nucleus. In this condition the male gametophyte has 
reached its maturity and fertilization may now take place. Should 
male cells fail to function in fertilizing an egg, as is frequently the 
case where there are a number of tubes in an ovule, they remain 
in this condition for a time and then disintegrate. Male cells 
have been found in ovules in which th yo was iderably 
advanced. 
Two unequal male cells are ae for Torreya taxifolia (14) 
and Cephalotaxus Fortunei (16), and the division of the body cell 
into male nuclei in C. drupacea (17). Miss RoBertson concludes 
that there are formed ‘‘a functional male nucleus” and a ‘“‘smaller 
male nucleus” in T. californica (18). In an earlier account (11) 
she had stated that the body cell divided into two nuclei of 
_ equal size. There is evident among the Taxineae a tendency 
toward the elimination of male cells in the formation of the so- 
called “male nuclei” only. The inequality of these nuclei or cells 
is another advance. A mere cutting off of the smaller nucleus © 
os from the body cell would be — = wie the final one, not - 
- cell functioning asa male cell... ~* Tatas the : male gametophyte : 
wt ie aes consists of the stalk and tube nuclei and the = 
two male « This is ae ine comps 
