344 
Walter Stiles. 
(Fig. 1). Its position is thus similar to that of Phyllocladus 3 No 
intermediate stages have been observed between the young stage 
of D. laxifolium and that of D. Colensoi in which the archegonia 
were ready for fertilisation. The following account refers to 
D. Colensoi. 
The number of archegonia varies in the cases observed from 
one to three, two being very common, and in respect of this small 
number D. Colensoi resembles Phyllocladus , 2 but is in marked 
contrast to the species of Podocarpus so far examined, for as the 
writer is shewing elsewhere, there may be as many as nineteen 
archegonia in P. nagi. The archegonia at the late stage examined 
appear to be embedded in the prothallus near its apical end (Fig. 2), 
but this appearance is probably due to a similar sequence of events 
to that which obtains in Phyllocladus. In that genus Miss Young 
describes the young archegonia as superficial, but when the pollen- 
tubes come in contact with their necks the adjacent tissues grow 
rapidly and so leave the archegonia at the bottom of cavities 
occupied by the pollen-tubes. 3 This same process would account 
for the condition of affairs seen in D. Colensoi. It would also 
appear that here, as in Cephalotaxus 4 , the archegonia may become 
completely enclosed by prothallus tissue if pollen-tubes do not 
reach their necks (Fig. 3). 
The peculiarity of neck development described by Miss Young 
in Phyllocladus and unrecorded for any other genus, also occurs in 
D. Colensoi. This characteristic consists in the separation of the 
four neck cells from the surrounding cells of the gametophyte, so 
that they appear as small detached cells against the middle of the 
outer wall of the archegonium. As in Phyllocladus they are, 
1 Young (1910), PI. IV., fig. 21. 
2 Op. cit., p. 85. 
3 Young (1910), p. 86. 
4 Coker, W. C. “ Fertilisation and Embryogeny in Cephalotaxus 
Fortunei .” Bot. Gazette, Vol. XLIII., p. 1, 1907. 
Fig. 1. Dacrydium laxifolium. Outline drawing of the ovulate structure, 
shewing the position of the young gametophyte. x 17. s, megasporophyll; 
e., epimatium; i, integment; n, nucellus ; g, gametophyte ; b, sterile bract. 
Fig. 2. D. Colensoi. Outline drawing of nucellus' and prothallus to shew 
the position of the archegonia. x 17. 
Fig. 3. D. Colensoi. Outline drawing of the upper part of the nucellus 
and female prothallus shewing one archegonium with a pollen-tube, and a 
second one without. The latter is surrounded by gametophytic tissue, x 57. 
F'ig. 4. D. 'Colensoi. Drawing shewing the male nuclei and the upper 
part of an archegonium with neck cells. X 2t>7. J ,, functional male nucleus ; 
2 , non-functional male nucleus ; p, prothallial (?) nucleus; n, neck of the 
archegonium. 
