54 
Sinnott . — The Morphology of the 
The Female Gametophyte and Embryo. 
Our knowledge of the female gametophyte and embryo of the Podo- 
carpineae has up to the present been practically confined to the results of 
investigations by Miss Young (21) on Phyllocladus alpinus, by Coker (2) on 
Podocarpus coriaceus , and by Stiles (13) on P. latifolius and P. macropliyllus , 
and to the fragmentary observations of Miss Gibbs (4) on several other species 
of the genus. It is now possible to add to this an almost complete account 
of the history of the macrogametophyte and embryo of Podocarpus Totara , 
P. nivalis , P. ferrugineus , P. spicatus } P. dacrydioides , and Dacryduim 
cupressinum , together with considerable information concerning P. elatus , 
P. spmulosus, P. vitiensis, and D. Bidwillii. 
In Eupodocarpus only a few months elapse between the appearance of 
the young female cones and the ripening of the seed, but the length of the 
period, besides being subject to a considerable amount of specific and in- 
dividual variation, depends also on climatic influences. It is very much 
shorter in the case of P. nivalis from the Southern Alps of New Zealand 
than in P. elattis from sub-tropical Queensland. The development of 
P. Totara in the North Island of New Zealand may be taken as fairly 
typical. Here the female cones are noticeable early in October, and 
pollination occurs about the middle of the month. The ovules reach 
nearly two-thirds of their mature size by the latter part of November, when 
fertilization takes place, and the seeds ripen in February. 
While the ovule is very small the megaspore mother-cell becomes 
differentiated from the rest of the nucellus by its greater size (PI. VII, Fig. 35 ). 
Its very large nucleus soon divides, as do the nuclei of the two resulting cells, 
and a linear tetrad of megaspores is thus formed, although there are some- 
times but three owing to the failure of one of the daughter cells to divide. 
Three of the four spores, usually those towards the micropyle, become 
abortive, and the single remaining one germinates to form the gametophyte. 
The occurrence in the mature ovule of two embryo-sacs, from the germina- 
tion of two spores, was observed rather frequently in most of the species. 
In all members of this sub-genus a group of uninucleate, densely proto- 
plasmic cells makes its appearance around the megaspore mother-cell, and 
later becomes a conspicuous layer of ‘ spongy tissue ’ surrounding the 
spores and the developing embryo-sac (Fig. 26 ). Whether or not this 
corresponds strictly to a true tapetum, its function is surely to nourish the 
growing spore. The absence of spongy tissue has been reported by Coker 
in P. coriaceus , but its presence has been noted in all other members of the 
sub-genus investigated by other writers. 
The details of spore germination are very much as in other Conifers. 
The nucleus soon divides and the resultant nuclei, which in their turn 
