46 



LECTURE IV. 



its anatomical structure and in its formation of wood and cortex, in the leaves 

 of the shoot, on the other hand, it is especially the outward form which 

 exhibits in astonishing variety the unbounded formative tendency of vegetable 

 substance. I may well expect from my readers that the ordinary external forms 



^7/e 



fed 



r\G. \\.~Clematis viticeUa (after Nägeli). End of the 

 shoot rendered transparent, to show the course of the 

 vascular-bundles (leaf-traces), which curve out above into 

 the (removed) leaves. 



Fig. 42-— Course of the vascular-bundles in a 

 monocotyledonous shoot of the Palm type, r 

 growing point ; j-j shoot-axis ; ** bases of leaves. 

 (After Kalkenberg.) 



of foliage leaves are to some extent familiar to them; that they know the chief 

 division of the same into lamina, petiole and sheath ; that the term stipule, and, 

 further, the terms entire, divided, lobed, pitmaJifid, compound leaves, &c., are not 

 quite strange to them. On the other hand, it accords with the main object of this 



