254 BOTANICAL GAZETTE [ocroser 
Flemming’s safranin-gentian-violet-orange G and Haiden- 
hain’s iron-alum-haematoxylin both gave excellent results, but 
the most satisfactory differentiation in fertilization stages was 
obtained with cyanin and erythrosin. This last combination, 
after the sections had been treated with acetic acid and chloro- 
form, gave details of structure not obtained by other methods. 
ERIGERON. 
Two species, E. Philadelphicus L. and E. strigosus Muhl., were 
examined. The following statements apply to both, as there is 
no difference in their embryo sacs, except in size. The devel- 
opment of the embryo sac does not differ essentially from that 
of other Compositae. The number of antipodal cells varies, and 
the one nearest the endosperm nucleus is frequently binucleate. 
The lower polar nucleus moves up and unites with the upper 
polar nucleus ( fig. r), which remains near the egg. The nucle- 
oli are very conspicuous, with highly refractive bodies scattered 
through them. 
The mature egg is pear shaped, its nucleus being very large 
(Jig. 2) and showing a fine network of chromatin. A vacuole 
near the middle of the egg is very conspicuous. 
The synergids are pear shaped, and the position of their 
nuclei is variable. The end nearest the egg invariably wets 
large vacuole, while the smaller end stains deeply and sometimes 
has a distinct constriction (fig. 2) between the nucleus and 
tip. | 
The embryo sacs in the ovules upon the edge of the head are 
larger than those at the center, several cases being een 
Which the sacs in the center of the head did not function. ; 
E. Philadelphicus the usual length of the embryo sac when reac} 
for fertilization is about 216 pw, the width being about 4° aoe 
endosperm nucleus at this stage is from 14.4 to 19.8 # 10 idom 
eter, its nucleolus being usually gu. The egg nucleus S€ 
varies from 10.8 w, with a nucleolus measuring 5.4 #- The 
sperm nucleus is usually about 16m distant fro 
Chamberlain has shown that in Aster Novae-Angliaet 
F 
: 
he nucleols a 
