318 BET. G. HESSLOW ON THE ABSORPTION OF EAIN" 



that moisture applied to internodes arrests death and decay in the 

 stems and axillary buds for variously prolonged periods ; for 

 efforts to develop axillary buds were frequently made, as well as 

 adventitious roots, these being apparently special instruments for 

 absorbing superficial moisture. 



3. On the Absorption by Leaves attached to Branches, and their 

 Power of Nourishing the Best of the Leaves on the Shoot. 



On July 23rd, 1878, a shoot of this year of Corylus Avellana, 

 with a subherbaceous stem, had three leaves lying with their 

 lower surfaces only on water. The shoot bore two large and two 

 small leaves sustained in the air. The whole shoot was perfectly 

 fresh and vigorous at the end of a week. On Aug. 3rd the larger 

 leaves began to die back from their apices, while the terminal small 

 ones were dead. Hence it was tar from entirely perishing after 

 10 days. 



A similar specimen had two large leaves with their upper surfaces 

 only lying on water, the remaining leaves as before in air. Like 

 the preceding, the whole kept perfectly fresh for the same time. 

 The apical leaves began to die about Aug. 3rd, or after 10 days. 



A similar specimen to these two, without water, was dead in 

 two days, the leaves being brown and brittle. 



Shoots of Lime, Elm, &c. treated as above gave similar results, 

 showing that the presence or absence of stomata is immaterial, 

 the upper surfaces of the above having none at all. 



These experiments entirely corroborate the results of Hales, 

 Bonnet, Baillon, Duchartre, Boussingault, &c, the general con- 

 clusion being that the duration of life in the specimen thus treated 

 depends upon the supply being equal to the demand. The ab- 

 sorbing-power is incontrovertible ; but the amount of foliage ex- 

 posed varies the demand upon the power of imbibition. 



To prove that the absorption and evaporation is not merely me- 

 chanical like a sponge, the following experiment will suffice. On 

 the 10th of June, 1876, a cut specimen of Nepeta Glechoma had two 

 leaves wrapped up in saturated blotting-paper. One internode 

 was exposed, bearing two other leaves also exposed to the air. **J 

 the 16th the latter was much discoloured. On the 22nd tbey 

 were nearly dead ; but the buds in their axils had been developing* 

 as well as smaller ones in the axils of the absorbing leaves. *v 

 the 27th both buds had borne four leaves each. One absorbing 

 leaf was now dead. On July 10th the other absorbing lea* 





