44 PKOSEKPINA. 



which break the light and the breeze, compared to what 

 with the frivolous and tremulous mind which is in us, we 

 could have had out of domes, or penthouses, or walls of 

 leaf. 



8. Secondly ; think awhile of its dark clear green, an<r 

 the good of it to you. Scientifically, you know green in 

 leaves is owing to * chlorophyll,' or, in English, to ' green- 

 leaf.' It may be very fine to know that ; but my advice 

 to you, on the whole, is to rest content with the general 

 fact that leaves are green when they do not grow in or 

 near smoky towns ; and not by any means to rest content 

 with the fact that very soon there will not be a green leaf 

 in England, but only greenish-black ones. And thereon 

 resolve that you will yourself endeavour to promote the 

 growing of the green wood, rather than of the black. 



9. Looking at the back of your laurel-leaves, you see 

 how the central rib or spine of each, and the lateral 

 branchings, strengthen and carry it. I find much con- 

 fused use, in botanical works, of the words Vein and Rib. 

 For, indeed, there are veins in the ribs of leaves, as mar- 

 row in bones ; and the projecting bars often gradually 

 depress themselves into a transparent net of rivers. But 

 the mechanical force of the framework in carrying the 

 leaf-tissue is the point first to be noticed ; it is that which 

 admits, regulates, or restrains the visible motions of the 

 leaf ; while the system of circulation can only be studied 

 through the microscope. But the ribbed leaf bears itself 

 to the wind, as the webbed foot of a bird does to the 



