Female Strobilus in Podocarpus. 547 
it proved quite sterile, showing the apical cavity and just one or two 
tracheides in the central cylinder. 
Coker ( 15 , p. 97) gives a similar instance in P. coriacea. In that case 
there were two prothallia in one ovule ; neither had formed archegonia, and 
in one three to four tracheides occurred in the central cylinder. 
In the fertile prothallia the earliest stage is shown in PL L, Fig. 36, 
where many proembryos form a complex which has excavated a cavity in 
the prothallial tissue below the archegonia, from each of which a proembryo 
seems to be formed. This is also the case in P. coriacea ( 15 , p. 101). 
These embryos were, with the suspensor tubes, rather contracted, but as far 
as could be made out resembled essentially those figured by Coker for 
that species. 
One suspensor had penetrated vertically into the prothallus (Fig. 36, 
sus.), showing a tiny embryo of about twenty cells at the basal end 
(Pig. 36, emb.). Immediately below it, in the central cylinder, the cells 
were densely packed with starch (Fig. 36, cen. cyl .). All the cells of the 
cylinder were multinucleate, mostly containing four nuclei (PI. LI, Fig. 40). 
This division must be very simultaneous, as the daughter nuclei are still 
enclosed in the limiting membrane. Miss L. Digby, in looking over the 
sections, came to the conclusion that the divisions are mitotic. This 
agrees with Coker’s ( 15 ) and Miyake’s ( 34 , p. 10) conclusions. The large 
peripheral prothallial cells showed very little starch, but dividing nuclei. 
In PI. L, Fig. 37 the disorganized remains of the embryos and 
suspensors still persist (< dis . emb. and sus.), but the cavity they lie in has 
shrunk, while the embryo has increased in size, the suspensor tubes being 
still traceable. Contraction of tissue is shown at the apex (Fig. 37) and 
similar contractions occur round the periphery of the prothallus, whose 
tissues are filled with starch. 
In PI. LI, Fig. 38 a section of the ovule with the ovuliferous scale is 
given. Stone cells are thickly scattered through the mesophyll, with no 
group arrangement. The vascular bundles show laminal branching (v.b. o. s.). 
The integument has very much shrunk, centripetal lignification having 
begun in the cell-walls, while nothing remains of the nucellus but the cap 
(Fig. 38 ,nuc. cap), still showing starch and traceable pollen-tubes. 
The megaspore membrane, though present, is very difficult to see, and 
cannot be dissected off, but in sections a thin line of cuticle persists in 
iodine and sulphuric acid. 
The cavity of the proembryo complex has quite closed up and the 
embryo is seen in the centre of the prothallus, with digested cell layers on 
each side, and a plug of the crushed and empty cells of the central cylinder 
at the base (Fig. 38, cen . cyl.). This embryo shows no differentiation. 
In Fig. 39 the cotyledons are differentiated, also the root apex. The 
embryo shows resin canals surrounding the phloem, which are present 
even in the cotyledons. Pressed between the cotyledons and spreading 
