Embryo of Cryptomeria Japonica. 423 
With the complete organization of the male cells, the history of the 
male gametophyte ends, and this is true for all other Conifers that have 
been investigated except Sequoia (Lawson, ’04). In this latter there is 
the additional step of the discharge of the male cell-nucleus into the 
archegonium. In Cryptomeria the entire male cell enters the archegonium 
as shown in Fig, 43. As we shall point out later, the two male cells enter 
separate archegonia, and therefore one pollen-tube brings about the 
fertilization of two egg- cells. 
The general characters of the male gametophyte of Cryptomeria are 
more distinctly of the Cupresseae type than of the Taxodieae. The 
behaviour of the pollen-tube and its spermatogenesis are very unlike 
Sequoia. Compared with Thuja (Land, ’02) and Taxodium (Coker, ’03) 
there is a very striking similarity. 
The Female Gametophyte. 
The stages in the development of the macrosporangium and the integu- 
ment follow very closely those in Taxodium (Coker, ’03) and Sequoia 
(Shaw', ’96, Lawson, ’04). There is one striking difference, however, and 
that is the advanced stage in the development of the integument before the 
differentiation of the sporogenous cells in the nucellus. Fig. 9 shows the 
appearance of the nucellus and integument in section from material collected 
March 7. As a rule, however, the micropyle is much more open than that 
shown in the figure. Material collected before March 6 showed no trace 
whatever of sporogenous cells in the nucellus, although the integument 
extended considerably beyond the apex of the nucellus, and in several cases 
the micropyle was found to be closed, shutting the pollen-grains within. 
The closing of the micropyle is brought about in very much the same 
manner as in Sequoia. The sub-epidermal cells and the epidermal cells in 
the upper region of the integument which form the inner wall become very 
much elongated in a direction at right angles to the micropyle. The result 
is that as these cells elongate, the micropyle becomes smaller until the 
channel is finally closed completely. 
One series of sections taken during the first week in March showed an 
interesting abnormality. There were two distinct sporangia developed 
within a single integument. This is shown in Fig. 10. These twin sporangia 
were not sufficiently developed to show the sporogenous cells, and as they 
were the only ones found out of the hundreds of preparations studied, they 
are no doubt abnormal and very exceptional. 
The sporogenous cells become differentiated early in March. It is 
very difficult at first to distinguish them from the ordinary sterile cells 
of the sporangium, but they soon become very densely packed with 
starch-granules, and become five or six times as large as the sterile cells 
