150 R. T. BAKER AND H. G. SMITH. 
vegetable kingdom. Continuing then to view the section 
as that of a true leaf, we find that comparatively little 
transfusion or conjunctive tissue occurs in this species, and 
also that it does not surround the stele in so uniform a 
character as obtains in some other genera of the Order, in 
fact, the meristele can hardly be said to exist in the form 
so common in needles of other Conifers. 
The phloem of the three-wedge shaped bodies or perhaps 
more correctly the stele, is surrounded by a mass composed 
of (1) endodermic cells, (2) transfusion tissue:—vessels 
which in the case of this and other species of Callitris 
appear to have no uniformity of arrangement when the 
section is taken either through, or clear of, the oil glands, 
as against the uniformity of such found in most. other 
Conifers. When, however, oil glands are present, the 
endodermic cells are found to extend round and encircle 
these bodies, and also to form a group or cluster between 
the stele and the epidermis at the base of the cavity formed 
by the concave ventral surfaces of the concrescence. The 
endodermis may therefore be said to be not well defined in 
Callitris leaves and in this respect there is a resemblance 
to Sciadopitys of Japan. The walls generally are circular 
in section, or having a slight tendency to hexagonal form, 
and they show no involutions or infoldings, so charac- 
teristic of Conifer leaf cells in general. 
In the preparation of the sections, their protoplasmic 
contents have been removed and so they invariably appear 
empty, and it is thus that they are easily differentiated 
from the cells with granulated content. These latter 
appear to take the place of, or to be an unusual form of 
transfusion tissue, if not then they are most probably fibre 
vessels. These play an important part in the metamorphosis 
of the leaf into cone scales; a subject that will be touched 
upon fully in a subsequent paper. The mesophyll needs 
