86 BOTANICAL GAZETTE [AUGUST 
has divided, forming a central cell and a primary neck cell; the latter 
gives rise by two divisions to a plate of four cells (figs. 2 5-27). An 
exceptional case is seen in fig. 29, where a division has occurred in 
each of the four cells. Cellulose walls (in this division), however, are 
not formed, the cells being separated merely by a Hautschicht, and 
in one of them not even a Hautschicht appears. The cytoplasm of 
the central cell is very delicate in the early stages, but gradually 
thickens up. The nucleus is rather small and lies at the upper end > 
close under the neck. 
There is an interesting peculiarity in the neck development of 
Phyllocladus which, so far as I know, has not been reported in any 
other genus. Miss Kitpant described the pollen tube as pushing 
its way into the archegonium with two apparently detached cells in 
front of it, which she thought were the remains of a crushed neck, 
Fig. 32 shows this stage, but there are four neck cells, and they are 
connected with the adjacent jacket cells by a distinct membrane. 
This membrane at first sight is easily mistaken for the wall of the 
pollen tube, but the latter is very thin and usually shrinks away 
from the archegonium in the preparations. 
The origin of this peculiar condition is found in a series of earlier 
stages. The young archegonia are superficial and the necks are — . 
covered by the heavy megaspore membrane (figs. 24-26). The pollen 
tubes at this time come in contact with the prothallus near the necks, 
and the adjacent tissues grow rapidly, leaving the archegonia at the 
bottom of considerable cavities which are occupied by the tubes 
(fig. 36). Im Cephalotaxus, according to COKER (4), the archegonia, 
in the absence of pollination, may be entirely inclosed by the growth 
of the lateral tissue. The megaspore membrane is always 4 little 
thinner at the micropylar end, but disappears entirely inside the 
archegonial cavities (fig. 37), apparently digested by the male gameto- 
phyte. Fig. 27 shows it beginning to disappear under the advancing 
tube. The growth of the female tissues and the pressure of the tube 
result in a lateral stretching, first of the neck, then of the adjoining 
jacket cells (fig. 28). The walls of these latter are able to resist the 
digestive action and enlarge enormously, until just before fertilization 
they appear as the membrane mentioned above (figs. 33-35)- 
An interesting situation is shown in fig. 34. The ovule contained 
