OH. III. DOWNWARD GEOWTH OF THE ROOTS. 



103 



the exactly opposite direction ; that is, towards the 

 zenith ! As this would be contrary to our universal, 

 everyday experience, possibly the philosophic, certainly 

 the unphilosophic, would wonder at it. Yet if we refer 

 the direction of the vertical growth of plants to gravity, 

 this is precisely what does take place : namely, the 

 first start of the root is with the attraction of gravity 

 towards the centre of the earth ; the first start of the 

 stem is against it, in the exactly opposite direction, — 

 that is, towards the zenith. And why the root should 

 obey, and the stem disobey, the otherwise universal law 

 of gravity, would still puzzle our philosophy, as I said 

 before. 



But difiicult as it would be to swallow the fact^ that 

 gravity should cause part of a plant to go with it and 

 part against, this is only half of what we have to swal- 

 low. For, actually, the ivhole vertical growth of plants 

 is against gravity ; and to say that gravity causes tliat 

 growth against itself, is as contradictory as to say that 

 darkness causes light. But, in fact, gravity acts as 

 much against the descent of the root in earth, as against 

 the ascent of stem in air. Gravity is a fine word, and 

 means weight. Attraction of gravitation is a fine term, 

 and means the attraction of weight : and, loosely speak- 

 ing, it may be said, that within this world the sole 

 effect of gravity or weight is, that the heaviest things 

 have a tendency to get lowest ; that is, that (though we 

 know not how or why) they are the most drawn 

 towards the centre of the earth, and, consequently, that 



