Jeffrey. — On the Structure of the Leaf in Cretaceous Pines. 209 
as in our specimens, by the large number of fascicular leaves. In the 
Kreischerville deposits only short-shoots have been found as yet. Our 
specimens also strongly resemble Pinites Solmsi of Seward (British 
Museum Reports, Fossil Plants of the Wealden, Part 2). His Fig. 2, 
PL XVIII, shows leafy short-shoots, which must have presented a strik- 
ing resemblance to our specimens in the living state, since they seem to 
have had the same long bractigerous base and numerous fascicular leaves. 
Turning our attention now to the internal structure of the leaves and 
axes of these curious brachyblasts, we find in Fig. 4, PI. XIII, a magnified 
view of one of the outer leaves shown in Fig. 2. The figure represents the 
leaf in its morphologically correct position with the xylem uppermost. 
The wood is only moderately well preserved, and the phloem has entirely 
disappeared, as is generally the case in Abietineous leaves from the 
Kreischerville deposits. The remainder of the leaf is composed of sclerified 
tissues, which contain towards the slightly flattened margins of the leaf two 
resin-canals. These present a remarkable contrast to those found in the 
fascicular leaves of living Pines, in the fact that they penetrate to the very 
base of the leaf and are occluded in this region by tyloses. The latter can 
be clearly distinguished in the figure. It has not been possible to follow 
with certainty the foliar resin-canals into the cortex of the short-shoot itself 
on account of the scantiness of well-preserved material ; but it is highly 
probable that, unlike the fascicular leaves of living Pines, those of Prepinus 
statenensis , as we propose to call our specimens, had their resin-canals con- 
tinuous with those of their axis and thus resembled the primary leaves of 
living Pines. The leaf-trace in Prepinus statenensis remained undivided in 
its course through the cortex of the axis of the short-shoot, and in this 
respect resembled the fascicular leaves of the living species of Pinus 
belonging to the sections Strobus , Cembra and Crayopitys. 
An important feature of the leaf-trace in our species is the fact that 
there is a considerable amount of true centripetal wood present. In Fig. 4, 
PL XIII, this can be distinguished by attentive examination, on the right of 
the fibrovascular bundle. Fig. 5 shows the bundle of this leaf more highly 
magnified. The preservation is unfortunately not very good ; but neverthe- 
less, on the right hand, radiating masses of xylem tissue, passing away 
centripetally from the face of the considerable mass of centrifugal wood, can 
be made out. These masses of centripetal wood, starting with a narrow 
base, expand in a fan-like fashion towards the upper surface of the leaf. 
The presence of this well-developed centripetal xylem in the leaf of 
a Cretaceous Pine-like Conifer appears to be not without significance, since, 
so far as is known to the writer, it is the first recorded case of the presence 
of such tissues in a Coniferous leaf, living or extinct. The transfusion 
tissues are intentionally disregarded in making this statement, since, as will 
subsequently be shown, these cannot properly be considered as representing 
