cn. IV, 



MISCELLAXEOUS. 



127 



thickness, cut off in the autumn, will become dried 

 throughout before the spring. But what can account 

 for the moisture of boughs, and even the most deli- 

 cate spray, exposed at great heights in the air, but 

 the constant supply of sap ? 



Indeed, if the first theory were correct, there is no 

 reason why plants should not live through the winter 

 out of the ground, and plants taken up in the autumn 

 should grow as freely when again put in in the spring- 

 as if they had just been taken up. The contrary of this 

 is the case ; the roots of plants taken up in the autumn, 

 as well as the plants themselves, unless they are ' laid 

 by the heel^ soon become dry. Why? Because the 

 roots are deprived of the power of imbibing moisture. 



I suppose there may be physiologists who think the 

 roots of trees useless at all times, except to fix tlie trees ; 

 for if there is no circulation in the winter the roots 

 are useless in the winter, and if, according to Liebig, 

 trees derive their nutriment from their leaves in the 

 summer, the roots are useless in the summer. I differ 

 in both cases. 



I have observed that, if the stem of a young tree 



grown in water is cut at the beginning of winter, the 



root immediately ceases to grow ; doubtless, because 



the stem is necessary to return the sap to nourish the 



root. If this theory is true, if there is a winter circu- if there is 



lation of sap, coppice-wood, hedges, and shrubs which circulation, 



coppice- 

 are intended to shoot up ao-ain, should be cut at the ^^ood 



^ ^ should be 



end of winter, — not at the beginning of winter. If g^'^of^^'® 



winter. 



