Reproductive S true hires in the Podocarpineae. 61 
The female gametophyte and embryo of Stachycarpus thus differ in 
several important particulars from those of the other sub-genera of Podocarpus . 
The reproductive cycle is extended through two seasons ; there is a very 
slight development of spongy tissue ; the number of archegonia is much 
reduced, but their size is greatly increased ; the neck is composed of but 
a single tier of cells; the first two embryonic mitoses take place in the 
upper portion of the archegonium, and the embryo almost from the first 
is composed of a body of cells instead of one. Several of these features are 
shared by the genus Dacrydium , but a still more striking resemblance is 
presented by the female gametophyte and embryo of Cephalotaxus . 
The only material at hand for a study of the female gametophyte in 
the sub-genus Nageia was some very young ovules of P. vitiensis. The 
embryo-sac in these was still very small, but was surrounded by a layer of 
spongy tissue, distinct but not as strongly developed as in Eupodocarpus. 
In tbe genus Dacrydium material was available for the study of the 
early stages of the female gametophyte in D. Colensoi and D. inter - 
medium , two closely related species. The later history was investigated 
in D. cupressinum , and some information was also obtained as to the 
structure of the mature archegonium and the development of the embryo 
in D. Bidwillii . 
In that portion of the genus represented by this last species the repro- 
ductive cycle is apparently completed in a single season, for in the Southern 
Alps in February there seemed to be but one generation of ovules, and these 
contained young or mature embryos. In D. cupressinum and its related 
species, however, tiny ovules which are just being pollinated are visible on 
the same branches with those of the previous year, which have reached 
their full size and in which fertilization and the development of the embryo 
is taking place. The life-history of this species therefore extends through 
two seasons, as in Stachycarpus . 
The growth of the megaspore and its germination into a linear tetrad 
occur in very much the same manner in Dacrydium as in Podocarpus , but 
in the former genus there is a less conspicuous development of spongy 
tissue. The vacuole, lined with free nuclei, increases in size and is very 
early filled by the centripetal growth of endosperm tissue, which occurs 
before the embryo-sac has reached half its final size. The endosperm cells 
at first contain but a single nucleus. A cone of multinucleate and more 
densely protoplasmic cells soon appears below the archegonial region, and 
by the time of fertilization there are several nuclei in every cell of the 
embryo-sac. The prothallial tissue often grows up over the archegonia. 
The latter appear while the sac is still very small, and in D. cupressinum 
are three in number at the apex of the gametophyte, each arising from 
a superficial cell and separated from the others by sterile tissue. The 
initial cell soon divides into primary neck and central cells. The former 
