584 Murrtll .— The Development of the Archegonium 
Two weeks after pollination the archegonial rudiments 
appear; a week later the necks are formed ; and two weeks 
after this the ventral canal-cell is cut off. Fertilization takes 
place five days after the ventral canal-cell is formed. It 
varies for the same and different trees much as pollination 
does, so that stages of fertilization may be obtained for a 
week or longer. After one season’s experience, it is possible 
to determine with tolerable accuracy the date of fertilization, 
but, after all, there is an element of chance that can be 
eliminated only by regular and abundant collections. I put 
up material from one to three times a day. The hour of 
collection seems to be of little consequence. The central cell 
was found in active division in cones collected at 10 a.m. in 
bright sunlight, in others collected at 7 p.m., and in still 
others on branches taken from the tree at 7 p.m., and kept 
in water until 11 p.m. Fertilization stages were abundant in 
cones collected at 9 a.m. and at 9 p.m. of the same day. 
Methods. 
The material was placed in the fixing solution within a few 
minutes after it was taken from the tree. Only the middle 
portion of the cone was used, as this part contains the best- 
developed ovules. In the younger stages, the terminal sterile 
portion of the scale was cut away, leaving the two ovules 
attached side by side; in older stages, the ovules were 
entirely separated from the scale, and, as the coats became 
hardened, they were cut away at the sides, exposing the 
endosperm directly to the fixing fluid. The endosperm 
should be quite well filled out before this is done, otherwise 
it may collapse. After the embryos are well established, it is 
well to remove the coats entirely. Many approved fixing 
methods have been tried, with variations in strength, time, 
and temperature, but for these studies none has been found 
equal to Mottier’s modification of Flemming’s solution, used 
fresh and allowed to act for twenty-four hours at about 30° C. 
During the preparation and fixing of the ovules the bottles 
were repeatedly shaken to ensure equal contact of fresh 
