AND DEW BY THE GEEEN PARTS OF PLANTS. 319 



perished ; consequently the buds immediately died. Duration 4 

 weeks and 3 days. 



4. Experiments to shoiv the Power of Absorption by Leaves and 

 Internodes to nourish loiver Leaves on the same Shoot. 



The possibility of an internode when wrapped up in saturated 

 blotting-paper nourishing leaves below it has been shown in the 

 case of Symplwricarpus. The following are instances in which the 

 leaves alone or with the internodes did the same. 



A frond of Nephrodium Filix-Mas had the terminal portion 

 wrapped up on July 3rd, 1876. No sign of shrivelling occurred 

 through that intensely hot month until Aug, 22nd, when a few 

 pinnules began to turn brown. Leaving town, the specimen was 

 neglected. Duration of observation 7 weeks. 



The terminal leaflet of Berberis aquifolia, as those of Dahlia, 

 Polemonium, Wistaria, &c, all nourished the basal leaflets well 

 for various lengths of time. 



Veronica Chamcedrys, Vinca major, &c. all illustrated the same 

 fact, that upper leaves can act as absorbents to supply lower ones 

 on the same shoot, the lowermost leaves, i. e. those furthest from 

 the absorbing ones, always dying first. Vinca major developed very 

 vigorous axillary shoots from the axils of its absorbing leaves, 

 similarly to the Nepeta Glechoma described above, the whole lasting 

 6 weeks. 



5. On the Nourishment of one Part of a Leaf by the Absorption 



of Water in another Part. 



The objection having been made by Duchartrethat when leaves 

 are laid upon water so that the edges are not touching it the 

 absorption is merely local, and that water is not transmitted to 

 the border, which consequently dries up, I have tried a large 

 series of experiments, placing (1) the apex only, (2) the basal part, 

 but not the cut end of the petiole, (3) the middle of the blade, 

 plunging both surfaces beneath the water in every case. Again, 

 I have taken the same parts, but placed (1) the upper side only, 

 (2) the lower side only on water. The results gave every degree 

 imaginable in the power of absorption. In some cases, e. g. Ipo~ 

 mcea purpurea, with the lower surface of the apical portion in 

 water the part in air rapidly perished, as this leaf is particularly 

 thin. In the majority of instances, however, it was at least two 



2a2 



