478 Stiles. — The Podocarpeae. 
formed by successive divisions come to lie in the parietal layer of cytoplasm 
surrounding the central vacuole. 
During the development of the young prothallus the layers of tapetal 
cells come to be more sharply marked off from the outer cells of the 
nucellus. Wall formation was not observed, but from the disposition of 
the cells before the appearance of the archegonia, there can be no doubt 
that the ingrowing primary prothallial cells are formed as in other Conifers. 
Up to the time of formation of the archegonia the cells of the prothallus 
are all uninucleate ; no sign of any binucleate condition was observed such 
as Lawson 1 found in Cryptomeria. 
The archegonia arise as superficial cells at the apical end of the pro- 
thallus. Coker found that these numbered from five to ten in P. coriaceus ; 
there is a similar number in the case of P. macrophylhis , but in P. latifolius , 
in the only case examined, there were as many as fourteen archegonia, while 
in each of the two ovules of P. nagi which contained archegonia the number 
was nineteen. Each archegonium is surrounded by a well-defined layer 
of jacket cells; these are conspicuous on account of their denser cytoplasm 
and larger nuclei. Occasionally, in P. macrophyllus , two archegonia occur 
within a common jacket, a fact of interest in comparison with Phyllocladus , 
where the same phenomenon has been observed. In P. nagi , to judge 
from the two cases examined, the phenomenon is more marked, as many as 
three archegonia being surrounded by a common jacket. The distribution 
of the archegonia in Podocarpus is thus like that in the Abietineae and 
Taxeae, but shows an approach to the state found in Cunninghamiap where 
the archegonia form a ring all enclosed in a common jacket, and surrounding 
a central mass of sterile tissue. 
Coker has observed a ventral-canal-nucleus in P. coriaceus . 4 In 
P. macrophyllus a well-defined ventral-canal-nucleus was not seen, but 
a safranin-staining mass present in the upper part of some archegonia may 
have been the disorganizing ventral-canal-nucleus. There is no evidence 
of this nucleus being cut off by a wall. 
In P. coriaceus 5 the neck consists of from two to twenty-five cells. 
Although such an extreme variation was not noticed in P. macrophyllus , yet 
the variation in number is certainly considerable in the mature archegonia, and 
as many as eighteen cells have been counted in the neck of one archegonium. 6 
Before fertilization the egg nucleus undoubtedly undergoes rapid in- 
crease in size. Unfortunately, measurements are not available for the 
young and old egg nucleus in the same species. In P. latifolius the 
diameter of the nucleus of the young archegonium is about 25 /x, while in 
1 Lawson (’ 04 2 ), p. 427. 2 Young (’ 07 ), p. 87. 3 Miyake (’ll), p. 1 1. 
4 Coker (’ 02 ), p. 98. 5 1 . c. 
6 The structure of the archegonium neck would thus appear to differ markedly from that of 
Phyllocladus and Dacrydium. See Young (TO) and Stiles (’ll). 
