VENATION OF MONOCOTYLEDONS AND CORMOPHYTES. 161 
as examples of the first variety ; and those of many Palms (jig. 
317) of the second. 
Or, the leaves may have a prominent midrib, as in the 
feather-veined variety of reticulated venation, giving off from 
its sides along its whole length other veins, which proceed par- 
allel to each other in a straight or curved direction towards, 
and lose themselves in, the margins (figs. 318 and 311, b) ; and 
are connected, as in the last variety, by unbranched veinlets. 
EPXGsol 7. Fic. 318. 
Fie. 316. 
Fig. 316. Leaf showing the variety of parallel venation usually called 
straight-veined; the margins are entire.——Fig. 317. Straight-veined 
variety of parallel venation, as seen in the leaf of the Fan Palm (Chame- 
rops).—Fig. 318. Curve-veined variety of parallel venation, as seen in 
the Banana,—Fig. 319. Forked venation of a Fern leaf (frond); the 
margins are crenate. 
The Banana, the Plantain, and allied plants, furnish us with 
examples of this variety. This latter variety is sometimes 
distinguished as the cwrve-veined, the former being commonly 
known as the straight-veined or parallel-veined. 
Venation of the Leaves of Cormophytes.—Besides the above 
varieties of reticulated and parallel venation as found in Dicoty- 
_ledons and Monocotyledons, the leaves (fronds) of Ferns, and 
those of other Cormophytes which have veins, present us with a 
third variety ; thus, in these the primary venation may be feather- 
veined or radiated-veined, but the whole of their principal veins 
M 
