456 Stiles . — The Podccarpeae . 
found on the upper as well as on the under surface. Pilger 1 would correlate 
this with the presence of palisade on both sides of the leaf, but in the leaves 
examined by the writer palisade was very feebly developed. The develop- 
ment of palisade on one side or on both sides of the leaf, as well as the 
extent of its development, probably, as in Angiosperms, depends mostly on 
external conditions. Bertrand’s statement that, except in P. elongatus , 
P. vitiensis , the Nageia section of Podocarpus , and Dacrydium , the upper 
face of the leaves is without stomata, 2 can be accepted no more than his 
statement that there is constantly under each bundle a single resin canal. 3 
In Podocarpus andinus , for example, stomata occur on the upper as well as 
Text-fig. 2. Diagrams of transverse sections of leaves of the Podocarpeae. Xylem is shown 
in black and transfusion-tissue is cross-hatched. In a and b the distribution of accessory transfusion 
tissue is indicated, and in c the distribution of epidermis, palisade, ‘ spongy ’ tissue, and stone-cells. 
a, Podocarpus macrophyllus, x 19; b, P. salignus , x 19 ; c, P. nagi, x 3 6 ; d, P. andinus, x 19 ; 
e, Dacrydium cupressinum, x 36 ; f, D. cupressinum (juvenile condition), x 36. 
on the under surface. 4 This last species may be regarded as the extreme 
type of this group as regards leaf structure (Text-fig. %, d), for in its leaves 
there is no trace of accessory transfusion tissue, nor is a sclerenchymatous 
hypoderm developed. Together with P . ferrugineus this species is classed 
by Bertrand in his section Prumnopitys , the chief characters of the section 
being want of both hypoderm and accessory transfusion tissue. 5 
4. Bertrand’s characteristics of the leaf of Dacrydium are absence of 
accessory transfusion tissue and of differentiation of the fundamental tissue ; 
the constant presence of stomata on the upper surface and of hypoderm 
below the epidermis. 6 The writer’s observations on D. cupressinum and 
1 Pilger (’ 03 ), p. 7. 2 Bertrand, 1 . c. 3 1 . c., cf. P. macrophyllus and P. amarus. 
4 The case of Microcachrys was unknown to Bertrand. 5 Bertrand (’ 74 ), p. 65. 
6 1. c., p. 67. 
