466 
Stiles . — The Podocarpeae . 
Later, a more complicated, and, in the lower part of the cone scale, 
a very variable, vascular structure occurs. Generally, the ovular supply 
given off from the upper surface of the sporophyll consists of about two 
bundles, although the number is not constant , 1 with inverse orientation of 
xylem and phloem as compared with the sporophyll. At the same time 
the sporophyll bundle divides into a row consisting of a variable number of 
bundles ; sometimes there are three, in other cases as many as five. The 
central bundle often divides partially, inasmuch as although the xylem 
separates into several groups, the phloems of the corresponding xylem 
groups remain joined laterally. This state of affairs was described formerly 
as the sporophyll bundle dividing more or less into a row of bundles , 2 
a description which M. Tison has evidently misunderstood . 3 The bundles 
on each side of the central one now bend round through two right angles 
so as to lie in the same line with the ovular supply given off from the upper 
surface of the sporophyll bundle ; the end bundles of the row, however, 
gradually die out, often moving further away from the central bundles ; 
these latter, generally to the number of three or four, bend round to the 
ovule, and fusing into two bundles just below it, enter the base of the 
nucellus and there terminate . 4 The xylem of these bundles is almost all 
centripetal in its development. No resin canals accompany the ovular 
supply. Higher up the scale the sporophyll bundle appears more compact, 
the xylem masses having reunited. Centripetal xylem makes its ap- 
pearance in the upper part of the scale in great quantity. The elements 
are short and wide and of irregular shapes, and have the appearance of 
transfusion tracheides . 5 Near the tip of one cone scale the single resin canal 
accompanying the sporophyll bundle had divided into three bundles lying 
side by side. This is interesting when it is remembered that one type of 
leaf in the genus Podocarpus contains three resin canals underneath the 
vascular bundle. 
IV. Microcachrys . The ovoid-globose cones of this genus are terminal 
on the branches and consist of about twenty sporophylls which are borne in 
alternating whorls of four ; the uppermost are always sterile. These 
sporophylls are tetragonal in shape, and each fertile scale bears a single 
ovule in a median position on the upper surface. As in Saxegothaea , the 
ovule is completely surrounded by an integument, partially surrounding 
which is an epimatium. 
The youngest material examined was in the megaspore-mother-cell 
1 Tison (’09) gives cases in which this supply bundle is absent altogether, but such have not 
been observed by the writer. 
2 Stiles (’08), p. 216. 3 Tison (’09), p. 150. 
4 Bertrand (’78), in a paper on ovular integuments, gives a figure of the ovule in which a vascular 
bundle, presumably the ovular supply, extends through the greater length of the epimatium. This 
representation is, however, without foundation in fact. 
5 Stiles (’08), p. 216, Figs. 33, 34. 
