Page:An introduction to physiological and systematical botany (1st edition).djvu/223

 Rh well, or better, by their foot-stalks as by their upper surfaces. Hazel-nut and Rose leaves, when laid with their backs upon the water, imbibe sufficiently to nourish other leaves on the same branch; so will one leaflet of a French bean supply its neighbour that does not touch the water.

Those who wish to repeat these experiments should be careful to choose full-grown healthy leaves, all as nearly as possible of the same age and vigour. It is also desirable that the precise species of plant should be recorded by its scientific name. For want of this, Bonnet, who despised method and nomenclature, has left us in uncertainty concerning several of the plants he examined. We ought to have been accurately informed what species of Poplar differed so remarkably in its power of absorption from the Aspen, another of the same genus. We ought likewise to have been told what Sun-flower, what Nettle, Amaranth and Mallows were examined; for want of which information the authority of such experiments is much impaired.

From the foregoing observations we learn