502 CONSERVATIVE ORGANS. [LECT. IX. 



section is angular, and the midrib on the under 

 surface resembles the keel of a boat, it is keeled 

 (carinata), 53. When, instead of one longitudinal 

 hollow, there are several linear depressions, the 

 surface is said to be furrowed (sulcata), 54 ; and 

 streaked (striata), if the depressions be super- 

 ficial, very narrow, and in parallel lines. If the 

 surface be depressed in the centre, and the leaf is 

 peltate, it is said to be navel-like (umbillcata) , 

 55: but if it rises and sinks alternately, in straight 

 angular furrows, like the folds of a fan, it is termed 

 folded (plicata) ; and waved (undulata) if in un- 

 dulations commencing from the midrib. When 

 the inequalities proceed from the portions of the 

 expansion between the network of the vascular 

 fasciculi being fuller than is requisite to fill the 

 vacant spaces of the meshes, and rising upwards, 

 the surface is wrinkled (rugosa), 56; and blis- 

 tered (bullata), when these elevations are still 

 more considerable; but when, on the contrary, the 

 fulness between the vascular fasciculi produces der 

 pressions, the surface is said to be pitted (lacu- 

 nosa velfavosa). 



When a leaf is covered with small hard tuber- 

 cles, which are more easily distinguished by the 

 finger than the eye, the surface is said to be sca- 

 brous (s cobra) : it is rough (asp era) when these 

 are more visible ; warty (verrucosa), 57, when 

 they are still larger and more solid ; and pustular, 



