attacked by gastric juice. How far globulin would be nutritious to
animals is not known. We thus see how differently the above specified
several digestible substances act on Drosera; and we may infer, as
highly probable, that they would in like manner be nutritious in very
different degrees both to Drosera and to animals.
The glands of Drosera absorb matter from living seeds, which are
injured or killed by the secretion. They likewise absorb matter from
pollen, and from fresh leaves; and this is notoriously the case with
the stomachs of vegetable-feeding animals. Drosera is properly an
insectivorous plant; but as pollen cannot fail to be often blown on to
the glands, as will occasionally the seeds and leaves of surrounding
plants, Drosera is, to a certain extent, a vegetable-feeder.
Finally, the experiments recorded in this chapter show us that there is
a remarkable accordance in the power of digestion between the gastric
juice of animals with its pepsin and hydrochloric acid and the
secretion of Drosera with its ferment and acid belonging to the acetic
series. We can, therefore, hardly doubt that the ferment in both cases
is closely similar, [page 135] if not identically the same. That a
plant and an animal should pour forth the same, or nearly the same,
complex secretion, adapted for the same purpose of digestion, is a new
and wonderful fact in physiology. But I shall have to recur to this
subject in the fifteenth chapter, in my concluding remarks on the
Droseraceae. [page 136]
CHAPTER VII.
THE EFFECTS OF SALTS OF AMMONIA.
Manner of performing the experiments Action of distilled water in
comparison with the solutions Carbonate of ammonia, absorbed by the
roots The vapour absorbed by the glands Drops on the disc Minute drops
applied to separate glands Leaves immersed in weak solutions Minuteness
of the doses which induce aggregation of the protoplasm Nitrate of
ammonia, analogous experiments with Phosphate of ammonia, analogous
experiments with Other salts of ammonia Summary and concluding remarks
117