Q4 PROCESS OF NUTRITION. CHAP. III. 



lived five weeks, and when moistened by the under 

 surface only five days. A leaflet of the French 

 Bean absorbed also a sufficient quantity of moisture 

 to nourish another leaflet that was still attached to 

 the same footstalk, though not touching the water. 

 Onthede- Out of sixteen trees or shrubs of different genera 

 tares of selected for the purpose of experiment, the leaves of 

 only two, the Lilac and Aspen, retained their ver- 

 dure equally long by whatever surface they were 

 moistened. But the leaves of the rest the Vine, 

 Pear, Cherry, Prune, Apricot, Walnut, Mulberry, 

 Oak, Hazel, Rose, &c. retained it longest when 

 moistened by the under surface. The following are 

 the most remarkable examples of relative capacity : 

 The leaves of the white Mulberry when moistened 

 by the under surface retained their verdure for 

 nearly six months, but when moistened by the 

 upper surface they retained it for only five or six 

 days. The leaves of the Vine, Poplar, and Walnut 

 faded almost as soon when moistened by the upper 

 surface, as when left without water altogether. The 

 leaves of the Hazel and Rose when moistened by 

 the under surface absorbed a sufficient quantity of 

 moisture to nourish also other leaves on the same 

 branch, though not touching the water.* 



Such was the result of the experiments of M. 

 Bonnet ; and the only thing to be regretted is that 

 he has not always been sufficiently accurate in spe- 

 cifying, beyond the chance of mistake, the plant on 

 * Recherches sur les Usages des Feuilles. 

 4 



