a non-albuminous, substance; and the absorption of a very small
quantity of the former would excite the leaves, and yet not decrease
the casein to a perceptible degree. Schiff asserts* and this is an
important fact for us that la casine purifie des chemistes est un
corps presque compltement inattaquable par le suc gastrique. So that
here we have another point of accordance between the secretion of
Drosera and gastric juice, as both act so differently on the fresh
casein of milk, and on that prepared by chemists.
A few trials were made with cheese; cubes of 1/20 of an inch (1.27 mm.)
were placed on four leaves, and these after one or two days became well
inflected, their glands pouring forth much acid secretion. After five
days they began to re-expand, but one died, and some of the glands on
the other leaves were injured. Judging by the eye, the softened and
subsided masses of cheese, left on the discs, were very little or not
at all reduced in bulk. We may, however, infer from the time during
which the tentacles remained inflected, from the changed colour of some
of the glands, and from the injury done to others, that matter had been
absorbed from the cheese.
Legumin. I did not procure this substance in a separate state; but
there can hardly be a doubt that it would be easily digested, judging
from the powerful effect produced by drops of a decoction of green
peas, as described in the last chapter. Thin slices of a dried pea,
after being soaked in water, were placed on two leaves; these became
somewhat inflected in the course of a single hour, and most strongly so
in 21 hrs. They re-expanded after three or four days.
* Lecons &c. tom. ii. page 153. [page 117]
The slices were not liquefied, for the walls of the cells, composed of
cellulose, are not in the least acted on by the secretion.
Pollen. A little fresh pollen from the common pea was placed on the
discs of five leaves, which soon became closely inflected, and remained
so for two or three days.
The grains being then removed, and examined under the microscope, were
found discoloured, with the oil-globules remarkably aggregated. Many
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