ABSOKPTION OF RAIN AND DEW BY GREEN PARTS OF PLANTS. 175 



Gain 

 per Cent. 



Tilia . .. . . . 16-40 



Querents 6-40 



Sambucus (old leaf) . . . 15*58 



„ (young leaf) . . 3-56 



Geranium. .... 11-32 



Urtica . . . . . 27-31 



Mercitrialis .... 14-50 



Tussilago 31-56 



Grass 35-00 



Hyacinthus .... 2-56 



Rumex 16-66 



Senecio ..... 8-44 



Fagns 24-05 



Philadelphus . . . . 8-33 









per 'cent. 



Viburnum 



. 6-84 



Bryonia (old leaf) 



. 16-49 



„ (young leaf) 



. 10-31 



Rubus .... 



. 14-28 



Carduus . . . 



. 10-71 



Nepeta .... 



. 8-89 



Malva .... 



. 909 



Ligustrum 



. 3-36 



Pulmonaria 



. 8-42 



Trifolium .... 



. 3116 



Syringa .... 



. 10-60 



Taxus .... 



. 1-94 



Berberis . 



. 0-57 



Aucuba (young shoot) 



. 2-20 



8. On the Absoeption of "Imitation-Dew." 



Finding that I could imitate dew very exactly by means of the 

 " spray," I adopted this plan, so as to apply what I call "imitation-dew " 

 to one, the upper or the under, surface of a leaf alone as required, or else 

 to both surfaces at once, as it is in Nature. 



A large series of very various and freshly gathered leaves was 

 experimented upon, the general result entirely corroborating previous 

 conclusions. The loss per cent, was almost invariably less when the 

 lower side only was covered with dew, which shows that absorption of 

 dew by that surface is more readily effected than by the upper. Such, 

 too, was the case, it will be remembered, with water. 



The certain inference that we may draw is that dew (in Nature) is 

 absorbed from below to supply the transpiration from above, if the leaves 

 are at all flaccid. 



Another series of some forty specimens consisted of leaves which 

 were left three hours to become flaccid. They were then weighed ; the 

 loss per cent, from the original weight when freshly gathered was 

 calculated. They were then treated with imitation-dew, there being three 

 examples of each species ; one had dew on the upper surface, another on 

 the lower, the third on both sides. In more than half of them they 

 gained weight after having been left to dry : the remainder had lost a 

 very small fraction per cent. This was due to the fact that they had 

 become quite dry some time before being reweighed ; hence they had 

 again begun to lose weight once more by transpiration. 



Hence this experiment entirely corroborated the one mentioned above 

 of the absorption of actual dew by slightly wilted leaves. 



9. On the Nourishment of Plants rooted in Pots by aid 

 of their Leaves and Green Internodes alone. 



A small healthy plant of Mimulus moschatus bearing three shoots 

 was growing in a pot. I ceased to water it on June 4. By the 8th the 

 shoots showed signs of wilting ; so I now placed the apices of two shoots 

 only in water. On the 11th the leaves on the third and exposed shoot 

 had all withered ; but the small buds in the axils of the lowest pair of 



