482 Stiles . — The Podocarpeae. 
period — all showed pollen-tubes that had penetrated a considerable way 
through the nucellus. 
On germination of the pollen-grain the inner layer of the wall bursts 
through the outer and forms the pollen-tube. Miss Young 1 has described 
the entry into the pollen-tube of the tube, stalk, and prothallial nuclei in 
D . intermeduim , the body-cell remaining behind in the grain. The same 
thing takes place in the case of D. cupressiniim . Although the tubes had 
penetrated a long way into the nucellus, in every case examined the body- 
cell remained behind in the grain (PL XLVIII, Fig. 25). In most cases the 
tube itself had grown straight down the nucellus and showed no sign of 
branching. Five or six nuclei were found in most of the tubes besides the 
nucleus of the body-cell. In the longer tubes, one nucleus, which occupied 
a position near the growing end of the tube, was much larger than the rest, 
and was probably the tube-nucleus. The remaining nuclei were in- 
distinguishable from one another, and would be the stalk-nucleus and pro- 
thallial nuclei ; there would thus be three or four of the latter. Four is the 
number found by Miss Young in the pollen-grain when ready for shedding, 
so, unlike Agathis , no further divisions occur among the prothallial nuclei 
after the shedding of the pollen. In one case a peculiar phenomenon was 
noticed. The growing nucellar tissue had apparently pressed against 
the pollen-tube so as to pinch off as it were the upper part attached 
to the pollen-grain, and thus containing the body-cell, from the lower 
part containing the tube-nucleus. In this case the tube-nucleus had pre- 
sumably divided, for two large nuclei were found together near the tip of the 
tube in the place generallyoccupied by the solitary tube-nucleus (PI. XLVIII, 
Fig. 26). Either nucleus of the pair was as large as an ordinary tube 
nucleus. This is, as far as I am aware, the only case so far recorded of the 
division of the tube-nucleus. In the pollen-grain and in the upper part 
of the tube starch grains are very abundant. Unfortunately, later stages 
of gametophytic development have not been available, so no further 
information can be given in regard to this genus in this connexion. 2 
II. Eupodocarpus . Material of two species of this subgenus has been 
used in this investigation ; these species are Podocarpus latifolius and 
P. macrophyllus . Only early stages of the former species were available, 
and the following description applies almost entirely to P. macrophyllus . 
The pollen-grains alight in a slightly concave receptacle formed by the 
apex of the nucellus. It was observed that in one case in P. macrophyllus 
the tube from a pollen-grain, that had come to rest at one extremity of the 
nucellus, grew along the top of the latter until it reached the middle of the 
concave portion. In all cases observed the pollen-tubes, after entering 
the nucellus, grow straight down until they reach the surface of the female 
1 Young (’07), p. 193. 
2 In Dacrydium Colensoi the body-cell nucleus gives rise to two unequal male nuclei (Stiles, ’ll). 
