some Notes on the Leaf-trace in the Ferns. 235 
of pinna-supply (to which I have referred as the ‘ combination-type ’). 1 
There is a combination sometimes of an ‘ extra-marginal ’ supply with 
a ‘ reinforcement ’ (Fig. 3) ; sometimes of a ‘ marginal * supply with 
a ‘ reinforcement ’ (Fig. 4). 
These arrangements appear most prominently among the Cyatheaceae, 
Aspidieae, and Pterideae. Further investigation of the members of the 
Fig. 3. Diagrams showing the 
extra-marginal type of pinna-supply, 
•with a ‘ reinforcement ’ derived from the 
abaxial curve of the leaf-trace, in 
Cibotium barometz (L.), J. Sm. 
Fig. 4. Diagrams illustrating the 
marginal type of pinna-supply, with a 
‘ reinforcement* derived from the abaxial 
curve of the leaf-trace, in Lonchitis 
pubescens, Willd. 
Pterideae, especially of the genera Hypolepis , Paesia , and Pteris , has shown 
that the appearance of the ‘ reinforcements ’ is partly dependent on the size 
of the leaf. For in Pteris decurrens , Pr., the marginal supply of the pinnae 
occurs alone in a fairly small leaf, while the marginal supply is reinforced 
in a leaf with large pinnae. In the genus Paesia , P. viscosa , St. Hil., has 
the marginal supply alone ; P. scabemla (A. Rich.), Kuhn, possesses a 
1 Trans. Roy. Soc. Edin., vol. lii, pp. 12, 14 (cf. ibid., vol. 1 , p. 352). 
