56 



MORPHOLOGY, OR COMPARATIVE ANATOMY. 



occur also in many Monocotyledons, the former, for example, in many 

 Palms, Musacese, Zingiberacese (fig. 68), &c. ; the latter in the Fan-palms, 



Fig. 66. 



Fig. 68. 



Fig. 67. 



Fig. 66. A parallel-nerved leaf. 



Fig. 67. A curvinerved leaf of Gloriosa superba, terminating in a tendril. 



Fig. 68. A penninerved leaf of Canna, with curved secondary nerves. 



Smilacese and Dioscoraceae, &c., where there is a transition to a curved- 

 ribbed condition (fig. 67), which, with the straight-ribbed (fig. 66), is 

 most common in the Monocotyledons. Straight-ribbed leaves occur not 



Fig. 71. 



Fig. 69. 



Fig. 70. 



A palminerved 

 serrate leaf. 



A penninerved entire leaf 

 with a marginal vein. 



A subrotund, entire, 

 penninerved leaf. 



^infrequently in Dicotyledons, as in Lathyrus, &c. The most important 

 distinction in the ribbing of the two groups is, that in Dicotyledons the 



