396 
Slopes and Kershaw .— The Anatomy of 
Prepinus japonicus, spec. nov. 
Description of leaf. In the specimen we have a length of about 
j-2 cm. of the leaf, in the course of which it does not appreciably vary in 
shape or diameter. The photograph on PI. XXVII (Phot, i) represents the 
shape of the leaf in cross section. It appears to have been slightly crushed and 
contracted, as the assimilating tissue between the sclerenchyma and the 
transfusion tissue shows, but this crushing has altered the shape of the leaf 
very slightly, if at all. The greatest diameter of the leaf is 1*5 mm., and it 
has five sides. 
In its shape the leaf closely resembles that of Prepinus statenensis 
as described by Jeffrey (’ 08 ). He notes (p. 208) that in its polygonal 
outline his leaf differs from any species of living Finns , and he correlates 
this form with the fact that the leaves are in fascicles in numbers together, 
and not as in modern Pines in clusters of two, three, or five. 
The epidermis is composed of small, squarish cells with very thick outer 
walls. The stomates are distributed on all sides of the leaf, and average 
about ten on the upper surface (the longest edge), six or seven on the two 
lower edges, and two or three on the lateral ones. They are of the normal 
Gymnosperm type, with sunken guard-cells placed at an oblique angle. In 
the intercellular space beneath them, fungal hyphae are to be seen in a good 
many cases in the specimen. Photograph 2, Pl. XXVII, shows an excellently 
preserved pair of guard-cells between the sclerenchyma patches on either side. 
The hypodermal sclerenchyma is much broken up owing to the numerous 
stomates, and forms triangular groups with the point of the wedge towards 
the centre of the group (see PI. XXVII, Phots. 1 and 2, and PI. XXVIII, Fig. 1, 
scl). The individual cells are often extremely thick-walled, and their pit canals 
are often visible. 
The assimilating tissue lies in small patches between the sclerenchyma 
and in a narrow zone outside the large central mass of transfusion tissue. 
In the sections this tissue is generally poorly preserved and crushed, but 
here and there its cells are visible, and show that the tissue was only five or 
six cells deep. In a few cells are indications that the walls were infolded as 
in the living Finns , but this is not very clear. 
The resin-ducts are two in number, laterally placed, slightly towards 
the upper side of the lateral edges of the leaf. They lie between the 
sclerenchyma and the transfusion tissue, almost filling the distance between 
them (see PI. XXVIII, Fig. 1,^). The duct is 0-07 mm. in diameter, and is 
surrounded by thirteen to fourteen epithelial cells. 
The vascular tissue , if the transfusion zone surrounding the bundle 
proper be included, bulks largely in the leaf. In this it closely resembles 
the American Prepinus. 
