544 Dutt. — Pityostrobus macrocephalus , L. and H. 
feature shared by both forms is the very slender cone-axis with its sur- 
rounding ring of uniform resin-canals. As far as can be judged the number 
of these canals does not vary in the different forms, and the consequent 
identity in phyllotaxis ratio constitutes another point of agreement between 
the cones. 
With regard to the ovules, the similarities are equally well marked. 
The integument, the nucellus, and the prothallus are conspicuously alike 
in structure and in state of preservation. Mr. Gardner's view that in P, 
ovata ‘ the seeds seem rounder ’ is not borne out by any of the slides 
examined. It is especially noticeable that the characteristic nucellar 
column and the well-developed gametophytic tissue are to be found in 
all the preparations. On the whole it seems justifiable to state that there 
are no important anatomical differences between the two so-called species. 
Taking this into account it seems probable that the differences in external 
character will turn out to be of less than specific value. At any rate it will 
be seen from what has been said that we can proceed with our discussion as 
if we were dealing with a single uniform type. 
We may now turn to the consideration of some features of the cone 
which seem to distinguish it from existing species of Finns . In the first 
place must be mentioned the very long and often fertile basal scales. 
Assuming that this is a real feature and not due to the base of the cone 
being broken off, it would seem that Carruthers is quite right in saying that 
it is a structure peculiar to these cones but not sufficient to separate them 
from the fossil genus Pinites. The very slender cone-^axis is a character 
of some importance. This is accompanied by a very weak development of 
the vascular tissue as a whole, which thus does not appear to show any 
correspondence with the demands which must be made upon it by the 
reproductive organs. The wood of the very narrow xylem cylinder, often 
separated into distinct bundles, is always of a very homogeneous character, 
the simple uniseriate medullary rays and the absence of resin-canals being 
particularly noticeable. If we regard the cone-axis as a seat of ancestral 
characters, it would seem that the presence of resin tracheides in the place 
of the usual ducts must be considered as a primitive feature. It is in 
accordance with the general weak development of the conducting tissue as 
a whole that we find that the sporophyll-traces are very small, and that the 
scale strands to which they give rise are also small and comparatively widely 
separated even in the basal region. In the nearly ripe cones of recent 
species of Pinus that I have examined the fairly thick vascular cylinder 
becomes markedly angular in the region of insertion of the large scale sup- 
ply, and the latter divides up almost immediately to give a row of bundles 
nearly touching each other and with a considerable development of secon- 
dary xylem. Although, however, it has not been found possible to match 
in the recent species the extreme reduction of the vascular tissue that 
