294 BOTANICAL GAZETTE [OCTOBER 
resembles the egg of Aster novae-angliae (CHAMBERLAIN 12) and 
that of many other plants as to shape and relation of nucleus and 
cytoplasm (fig. 17). 
The nuclei of the synergids do not always have the same posi- 
tion (figs. 15-17, 19). In the youngest sac of the series (fig. 15) 
there is a large vacuole at the base of either synergid, with the 
nucleus above and near the micropylar end. Fig. 16 illustrates a 
condition in which the synergid nuclei have moved down halfway, 
and in one cell there is a vacuole on either side of the nucleus, while 
in the other there is a large vacuole below it but only a small one 
above it. In fig. 17 one nucleus has moved entirely below the 
vacuole and is near the membrane at the end of the cell, whereas 
the other nucleus is still between two or more vacuoles. In a 
much older embryo sac (fig. 19) the synergids are longer, the 
nucleus of each is at its base, and a large vacuole appears above 
the nucleus. At all stages in the growth of the egg apparatus the 
synergids contain a fairly dense cytoplasm at the apex. It seems 
clear that the position of the synergid nucleus varies in relation 
to the age of the sac; that at first it is near the micropylar end 
of the synergid and above the vacuole; that later it passes the large 
vacuole and moves down to the opposite end of the cell. When 
the egg apparatus is mature the two nuclei are at the base of the 
cells, near the egg nucleus, and just below the large vacuoles 
(fig. 19). 
According to the literature on the subject the position of the 
synergid nuclei in different plants may vary in relation to the large 
vacuole of the cell, but I have found no suggestion that the vari- 
ation in a given species represents different stages in develop- 
ment. CHAMBERLAIN (12) gives the situation of the nuclei in 
Aster novae-angliae as varying in position from one end of the cell 
to the other but most frequently near the middle, the large vacuole 
being usually at the chalazal end of the synergid. GuIGNARD (19) 
says that in the Leguminosae the vacuole is usually at the base of 
the cell and the nucleus is central, but the vacuole may sometimes 
be above the nucleus. Barnes (6) in Campanula americana, 
GUIGNARD (24) in Hibiscus Trionum, and STRASBURGER (42) in 
Wikstroemia indica von Buitenzorg find the nucleus above the 
