sit 
1897 ] LIFE HISTORY OF LILIUM PHILADELPHICUM 413 
special attention. These special investigations were undertaken 
by Mr. Chamberlain and Mr. Schaffner, who have made an inde- 
pendent presentation of their results, for which they are entirely 
responsible. This contribution, therefore, is made up of three 
distinct and independent papers, each with its own plates, but 
naturally brought together by the nature of the subject. 
My own part is the organization of observations made by the 
group of students referred to, in so far as they pertain to the 
embryo sac, fertilization, and the embryo. Mr. Chamberlain, 
from his own observations, deals with the pollen grain; while 
Mr. Schaffner presents his own observations and conclusions in 
reference to certain cytological phenomena connected with the 
“reduction division” in the embryo sac. 
The material used was fixed in Flemming’s weaker solution, 
Merkel’s fluid, 1 per cent. chromic acid, 1 per cent. chromic acid 
- with a trace of acetic acid, and picric acid. 
Xylol was used almost exclusively to precede the paraffine 
bath. Serial sections were cut with a Thoma microtome, usually 
5 Or 10m thick, and occasionally but 1p thick. 
A large number of stains and combinations was used. Cyanin 
and erythrosin proved excellent for most stages in the develop- 
ment of the macrospore; Delafield’s haematoxylin is to be rec- 
ommended for embryos; safranin with gentian violet and orange 
G gave good results in staining pollen grains; Heidenhain’s 
iron alum haematoxylin used alone or with erythrosin or orange 
G gave by far the best preparations for cytological study. 
| 1 
THE EMBRYO SAC AND ASSOCIATED STRUCTURES. 
JOHN M. CouLtTeER. 
(WITH PLATES XXXII-XXXIV) 
a The results here recorded traverse ground which has become 
familiar. It will not be necessary, therefore, to make > 
_ ra apes of all the aimee om but to discuss -~ 
