14 
Miyake, The development of the gametophytes etc. 
the tip, and right below it, is one large vacuole occupying the 
center of the egg (figs. 84—87). The structnre of the egg-nncleus 
does not seem to differ mnch from that of the other Conifers. It 
contains a more or less interrupted reticuluin, which appears some- 
wkat granulär and may be composed of an irregulär network of 
linin in which chromatic grannles are imbedded (figs. 84—86, 
88—90. 112). 
The cytoplasm of the egg presents a finely granulär appearance 
and contains no such bodies as can be compared with the proteid- 
vacuoles of the Abietineae. Ouly some more or less deeply-staining 
granules are often fonnd scattered in the cytoplasm (figs. 84—86). 
Fertilization. 
Fertilization seems to take place one or two days after the 
cntting off of the ventral canal-nucleus and immediately after the egg- 
nncleus reaches its matnre size. The date varies by season and 
locality. It differs also even in the same tree. In rny material, 
most of the fusing nuclei were found between July 3 and 5. 
Generally speaking, we may say that in the middle part of Japan, 
the fertilization of Cunninghamia sinensis occurs during the first 
week of July, i. e., about three months after pollination. 
As was stated before, the pollen-tube reaches the depression, 
the archegonial chamber, above the archegonial complex at the 
end of June. The division of the generative cell, which is situated 
at the tip of the tube, seems to take place about the same time 
as that of the central cell of the archegonium. The two sperm- 
cells, formed as the result of the division, become somewhat en- 
larged and filled with starch, as was already described. Now the 
sperm-cells are ready for fertilization, and the stalk- and tube- 
nuclei are found more or less disorganizing right below them 
(figs. 35, 87). 
Only one sperm-cell enters each archegomum. No case was 
fonnd in which two sperm-cells entered into the same egg as it 
appears sometimes to be the case with Taxodium (Coker, 1903). 
The sperm-cell advances toward the egg-nucleus, and its nucleus 
soon comes in contact with the egg-nucleus. The sperm-nucleus 
now flattens itself against the egg-nucleus (figs. 88—90). The 
diameter of the sperm-nucleus, before entering into the egg, is 
abont half of the egg-nucleus (figs. 35, 90, 107, 112). The former 
seems to enlarge somewhat after entering the egg, and at the time 
of conjugation, it approaches the egg-nucleus in size. though some- 
what smaller than the latter (figs. 88- 90). A similar enlarging 
of the sperm-nucleus in the egg was also described by Coker 
(1903) in Taxodium and by Lawson (1904b) in Crgptomeria. 
The fusing nuclei retain their identity for sometime, the two 
nuclei being separated by a membrane. They are surrounded by 
a dense sheath of stareh-granules (figs. 89, 90, 113). There is no 
donbt that the greater part of the substance of the sheath is de- 
rived from the sperm-cell. A similar starch-sheath was observed 
in Taxodium (Coker, 1903) and Oryptomeria (Lawson, 1904b). 
