6B0S8 ANATOMY OF TEE AN0I08PEBM8. 299 



said to be crenate (scalloped); wlien they are large, cleftldbed, or 

 cleft. (Fig. 193.) 



When the projections are pointed and small, the Wade is said to be 

 serrated (saw-toothed) ; when larger and standing out from the mar- 



Fio. 193.— Diagram showing the principal forms of margin. 



gin, dentate (toothed) ; when still larger, incised. (Pig. 193.) When 

 the projections are hardened and sharp-pointed, the leaf is spiny. 



Venation of the Blade. — The framework of fibro-vascular bun- 

 dles {veins) running through the leaf always conforms to the general 



LON 



,NAL. 



Fig. 194.— Diagram showing principal kinds of venation. 



and particular outlines of the blade. There is commonly a mid- 

 vein (midrW) running centrally from base to apex, and secondary 

 ones which run centrally (or nearly so) through the lobes. We 

 have thus a pinnate venation, in pinnately lobed leaves, and radiate 

 venation, in radiately lobed leaves. Moreover, a modified form of 



