THE GREEXIVOOD TREE. 143 



directly out of the air ; and that when they die or get 

 consumed, they return once more to the atmosplicre from 

 which they were taken. Trees undeniably eat carbon. 



Of course, therefore, all the ordinary unscientific 

 conceptions of how plants feed are absolutely erroneous. 

 Vegetable physiology, indeed, got beyond these concep- 

 tions a good hundred years ago. But it usually takes 

 a hundred years for the world at large to make up its 

 leeway. Trees don't suck up their nutriment by the 

 roots, they don't derive their food from the soil, they 

 don't need to be fed, like babies through a tube, with 

 terrestrial solids. The solitary instance of an orchid 

 hung up by a string in a conservatory on a piece of 

 baik, ought to be sufficient at once to dispel for ever this 

 strange illusion — if people ever thought ; but of course 

 they don't think — I mean Other People. The true 

 mouths and stomachs of plants are not to be found in 

 the roots, but in the green leaves ; their true food is not 

 sucked up from the soil, but is inhaled through tiny 

 channels from the air ; the mass of their material is 

 carbon, as we can all see visibly to the naked eye 

 when a log of wood is reduced to charcoal : and that 

 caibon the leaves themselves drink in, by a thousand 

 small green mouths, from the atmosphere around them. 



But how about the juice, the sap, the qualities of the 

 soil, the manure required? is the incredulous cry of 

 Other People. What is the use of the roots, and 

 especially of the rootlets, if they are not the mouths and 

 supply-tubes of the plants? Well, I plainly perceive I 

 can get ' no forrarder,' like tlie farmer with his claret, 

 till I've answered that question, provisionally at least ; 



