32 



ORGANOGRAPHY. 



of different kinds of leaves be examined, it will be found 

 that two types prevail. The one is represented by such 

 leaves as the Lily, Flag, Grass, 

 Corn, Wheat, etc., in which a 

 Dumber of conspicuous veins ex- 

 tend from the base to the apex 

 of each leaf, approximately par- 

 allel to each other, and this fact 

 has suggested the name par- 

 « allel-veined (Fig. 40). The 



other type is seen in the Oak, Elm, Maple, Catnip, 

 Mallow, Dock, etc. The veins here form a net- 

 work, and are said to be netted- veined, or reticio- ^^ 

 lated. Of the latter there are two sorts : the veins may 

 branch from a midrib (Fig. 41), when 

 they are pinnately-veined (Lat. pinna, 

 feather) ; or they may branch from 3, 5, 7, 

 etc., ribs (Fig. 42), in which case they are 

 palmately-veined (Lat. palma, palm). 

 36. The principal shapes assumed by 

 leaves are : linear, narrow, long, and of the same breadth 

 throughout (Fig. 43) ; lanceolate (Lat. lancea, lance), 



Fig. 40, Parallel-veined leaf. Fig. 41. Pinnately-veined leaf. Fig. 42. Palmately- 

 veined leaf. Figs. 43-48. Shapes of leaves : 43. Linear ; 44. Lanceolate ; 45. Ob- 

 long ; 46. Elliptical ; 47. Oval ; 48. Ovate. 



