See sae, eee 
PR te ee 
Te a Oe ey eT EE TS ce 
PRS ene 
oh al 
ie i a a a la col a ae aa a a 
1925] ' COULTER & LAND—TORREYA TAXIFOLIA 165 
down the nucellar cap, then advanced spirally downward and out- 
ward until it reached the peripheral cells of the nucellus, and after 
destroying several of these it turned abruptly inward, penetrated the 
nucellus at the level of the archegonium, crossed the top of the endo- 
sperm, and discharged its contents into the archegonium on the farther 
side. In another instance, such a pollen tube had entered the inner 
integument and destroyed some of its cells before turning back into 
the nucellus. It is very common for the pollen tube to push into the 
sac at its free nuclear stage, making a deep invagination, often to the 
middle; from this pocket the tube turns back again into the nucellus. 
It is of interest to note in this connection that the usually solitary 
archegonium is never centrally placed in the endosperm, and the 
pollen tube enters the sac to one side of it (fig. 16). 
In all the wanderings of the pollen tube, the body cell, stalk 
nucleus, and tube nucleus are conspicuous. The division of the 
generative cell was not observed, but that it occurs very early in 
the development of the tube is evident. The body cell is relatively 
very large, with a conspicuous nucleus and investing cytoplasm, and 
was always found consorting closely with the stalk and tube nuclei 
(figs. 13 and 14). 
e division of the body cell just before fertilization results in 
unequal male cells (fig. 23), almost exactly resembling those of Taxus. 
It is not a case of the extrusion of one nucleus from the common 
cytoplasm, as observed by CoKER (2) in Podocarpus, but the cyto- 
plasm is unequally divided, so that there are two distinct and naked 
male cells very different in size. The whole cavity of the pollen 
tube surrounding the cells and nuclei is rich in starch and other food 
materials (fig. 13). 
A consideration of the time involved in these various events shows 
that a period of about fifteen months elapses between the first appear- 
ance of the microsporangiate strobilus and fertilization, divided as 
follows: June, first appearance of strobilus; August, first appearance 
of stamineal primordia; September, distinct differentiation of spor- 
angia; April, shedding of spores; August, fertilization. The stro- 
bilus was first observed in July, but in such a condition that it must 
have been evident in June, if not earlier. In comparing this schedule 
with that given by Miss ROBERTSON (8) for T. californica, it is evident 
