Stiles. — T he Podocarpeae. 
481 
After the cutting off of the two primary prothallial cells, the antheridial 
cell divides into the tube-cell and the generative cell. The latter is cut off 
from the former in much the same way as the primary prothallial cells. 
This division is followed by the division of the generative cell into what 
may be called the stalk-cell and the body-cell, but the division in all the 
Podocarpeae is an anticlinal one, so that the products of division lie side by 
side. Jeffrey and Chrysler have described in Podocarpus ferrugineus and 
P. polystachyus 1 an appearance as of a second derivative of the generative 
cell besides the so-called stalk-cell, and a similar appearance was noted by 
Mr. Brooks and the writer in P. spinulosus . 2 Miss Young has suggested 3 
that this appearance is due to the partial encircling of the body-cell by the 
stalk-cell, and this may well be so in P. spinulosus. 
In all the Podocarpeae the limiting membranes of the prothallial cells 
and stalk-cell break down, and the nuclei come to lie free in the general 
cytoplasm. Thus, at the time the grain is shed the body-cell is the only 
one surrounded by a definite membrane. In Podocarpus spimdosus it was 
observed that at this stage the tube-nucleus is the largest in the grain, and 
the same is true of P. andinus and P. latifolius. In no instance in P. andinus 
were more than eleven nuclei observed in one pollen-grain, so there is 
presumably no second derivative of the generative nucleus in this species. 
B. Later History (Development of Pollen-tube). 
The development of the gametophyte beyond the stage just described 
has been observed in very few cases. Miss Young 4 has observed stages in 
Dacrydium laxifolium and D. intermedium in which the pollen-tubes have 
commenced to grow through the nucellus. Only in two cases, however, 
has the development been followed further, in Podocarpus coriaceus 5 and in 
Phyllocladus sp . 6 These are the species in which the least development of 
prothallial tissue has so far been recorded, so that special interest attaches 
to the investigation of the later stages of the gametophyte in forms more 
typical of the order in respect of prothallial development. Observations 
have been made on the later history of the microgametophyte in Dacrydium 
cupressinum, Podocarpus macrophyllus , P . latifolius^ and P. nagi. As in the 
case of the female gametophyte, it is to be regretted that the difficulties 
of collection of three of these species did not permit of the use of fixatives 
suitable for cytological work. 
I. Dacrydium cupressinum. In this species it would appear that 
fertilization takes place a year after pollination. Ovules collected near 
Wellington, New Zealand, in July — that is, in the middle of the resting 
1 Jeffrey and Chrysler (’07). 
3 Young (’10), p. 83. 
6 Coker (’02), p. 94. 
2 Brooks and Stiles (’10), p. 309. 
4 Young (’07). 
6 Young (’10), p. 84. 
