III. THE LEAF. 51 



we know nothing whatever about its causes; nay, the 

 strangeness of the reversed arterial and vein motion, with- 

 out a heart, does not seem to strike anybody. Perhaps, 

 however, it may interest you, as I observe it does the bot- 

 anists, to know that the cellular tissue through which the 

 motion is effected is called Parenchym, and the woody 

 tissue, Bothrciichym ; and that Parenchym is divided, by 

 a system of nomenclature which " has some advantages 

 over that more commonly in use," * into merenchyma, 

 conenchyma, ovenchyma, atractenchyma, cylindrenchyma, 

 colpenchyma, cladenchyma, and prismenchyma. 



20. Take your laurel branch into your hand again. 

 There are, as you must well know, innumerable shapes 

 and orders of leaves ; there are some like claws ; some 

 like fingers, and some like feet; there are endlessly cleft 

 ones, and endlessly clustered ones, and inscrutable divis- 

 ions within divisions of the fretted verdure ; and wrinkles, 

 and ripples, and stitchings, and hemmings, and pinchings, 

 and gatherings, and crumplings, and clippings, and what 

 not. But there is nothing so constantly noble as the pure 

 leaf of the laurel, bay, orange, and olive; numerable, 

 sequent, perfect in setting, divinely simple and serene. 

 I shall call these noble leaves Apolline ' leaves. They 

 characterize many orders of plants, great and small, 

 from the magnolia to the myrtle, and exquisite 'myrtille' 



* Lindley, 7 'Introduction to Botany, 'vol. i., p. 21. The terms "wholly 

 obsolete," says an authoritative botanic friend. Thank Heaven ! 



