6 BOTANICAL GAZETTE [JANUARY 
there is no pollen tube above an archegonium, the growth of the 
prothallium may close the pit and bury the archegonium completely. 
Both sperm cells are discharged into the egg, but the two vegeta- 
tive nuclei may remain behind. The larger sperm cell advances to 
the egg nucleus, the sperm nucleus sinks into it, and the sperm proto- 
plasm gradually surrounds the fusing nuclei, exactly as I have already 
described for Taxodium. Figs. 11, 12, 13, 14 show stages of approach 
and fusion. The second sperm cell remains above (figs. I1, 12) 
and may approach pretty close to the fusion nucleus (jig. 14). 
ARNOLDI (I) says that soon after the sperm cells enter the archego- 
nium, the protoplasm becomes mixed with that of the egg. He does 
not observe the sperm protoplasm investing the fusion nucleus. 
The contribution of the sperm protoplasm to the proembryo 
has also been observed in Torreya by Miss RoBERTSON (17) and 
CouLTER and Lanp (6), in Cryptomeria by ARNOLDI (1) and LAWSON 
_ (11), in Juniperus by Norén (15), and in Sequoia by ARNOLDI (2). 
In Lawson’s (10) work on Sequoia he does not confirm ARNOLDI, 
but finds that only a very small amount of the sperm protoplasm 
enters the egg with the nucleus, the rest remaining behind in the pollen 
tube. This odd behavior is similar to the process of fertilization in 
Taxus as described by BELAJEFF (3). There is no starch in the sperm 
cells of Cephalotaxus such as is found in Taxodium, Sequoia, Cryp- 
tomeria, and Juniperus. 
The first division of the fusion nucleus occurs near the center of 
the archegonium. The spindle is very small compared with the size 
of the nucleus and is entirely intranuclear. Fig. 14 shows an early 
stage in this division. The sperm protoplasm has not yet entirely 
invested the nucleus. In fig. 15 the division is complete and the 
two nuclei are approaching the base of the archegonium, Two 
extra nuclei are shown above—one is probably the second sperm 
nucleus, The next division occurs before the proembryo has reached 
the base of the archegonium. Three of the four nuclei produced 
by this division are shown in jig. 106. 
In jig 17 is shown the eight cell-stage which now occupies the 
base of the archegonium. Five of the eight nuclei are in the section. 
These eight nuclei now divide again simultaneously, and after the 
formation of the sixteen daughter nuclei, cell walls are formed for 
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