406 Lawson .— The Garnetophytes and 
the tube, while the tube-nucleus advances with the growing tip. Early in 
July, however, the stalk-nucleus follows in the wake of the tube-nucleus 
down the tube, leaving the body-cell in its original position in the spore 
end. This shifting of the free nuclei in the tube is shown in Figs. 9 and 10. 
As the tubes grow almost in a straight line down through the soft tissue 
of the pollen-cushion, no difficulty was met with in obtaining complete 
longitudinal sections showing all the essential changes during their develop¬ 
ment. In Fig. 7 is represented the general course of the tube as it appeared 
three months after pollination. As shown in Figs. 9 and io, there are large 
numbers of starch grains in the cytoplasm of the tube, and the amount 
increases as development advances. 
Up till this time the male gametophyte has undergone an uninterrupted 
development, so that about the middle of July we find the body-cell and 
the stalk-nucleus fully organized, and the pollen-tube lying embedded in 
the soft tissue of the pollen-cushion. And in this condition it remains 
until the following spring. Occasionally it was observed that the tube may 
penetrate for a short distance into the firmer tissue of the nucellus below 
the cushion, but this was quite exceptional. No further nuclear changes 
take place in the tube until eleven months later. In this regard the male 
gametophyte of Sciadopitys shows a marked resemblance to Finns (Coulter 
and Chamberlain, ’01 ; Ferguson, ’ 04 ), but is quite unlike Cephalotaxus 
(Lawson, 5 07 ), which also takes two seasons before fertilization is accom¬ 
plished, but where the pollen remains practically dormant for a year after 
pollination. 
Early in June of the following year—that is, about fourteen months 
after pollination—the body-cell in Sciadopitys gradually descends into the 
tube, and finally occupies a position near the tip a little distance behind 
the stalk- and tube-nuclei. But during this migration of the body-cell the 
tube has not only penetrated the entire nucellar tissue, but has reached 
one of the archegonial chambers. In number and position those chambers 
resemble those of Pinus , but are very much deeper. In Fig. 48 the body¬ 
cell is represented in the region just entering the archegonial chamber, 
while the tip of the tube has reached the neck-cells. Fig. 11 shows, with 
the details more highly magnified, a portion of the pollen-tube containing 
the body-cell. In its descent in the tube the body-cell loses its spherical 
form and appears considerably elongated. It retains, however, its distinct 
membrane which separates it from the cytoplasm of the tube. The nucleus 
is very large and perfectly spherical, and as it approaches the tip of the 
tube it shows evidences of preparing for mitosis. The spindle of this 
division was not found, but several tubes showed the stages immediately 
following mitosis. The division of the body-cell evidently takes place in 
the tip of the tube immediately over the neck-cells of the archegonium, 
and it results, not in the formation of two cells as in Sequoia and the 
