oblong and two-armed ones. The former do not so commonly become brown,
and are acted on more slowly. We may therefore infer that they differ
somewhat in their natural functions.
It is remarkable how unequally the glands on the bladders on the same
branch, and even the glands of the same kind on the same bladder, are
affected by the foul water in which the plants have grown, and by the
solutions which were employed. In the former case I presume that this
is due either to little currents bringing matter to some glands and not
to others, or to unknown differences in their constitution. When the
glands on the same bladder are differently affected by a solution, we
may suspect that some of them had previously absorbed a small amount of
matter from the water. However this may be, we have seen that the
glands on the same leaf of Drosera are sometimes very unequally
affected, more especially when exposed to certain vapours.
If glands which have already become brown, with their primordial
utricles shrunk, are irrigated with one of the effective solutions,
they are not acted on, or only slightly and slowly. If, however, a
gland contains merely a few coarse granules, this does not prevent a
solution from acting. I have never seen [page 423] any appearance
making it probable that glands which have been strongly affected by
absorbing matter of any kind are capable of recovering their pristine,
colourless, and homogeneous condition, and of regaining the power of
absorbing.
From the nature of the solutions which were tried, I presume that
nitrogen is absorbed by the glands; but the modified, brownish, more or
less shrunk, and aggregated contents of the oblong glands were never
seen by me or by my son to undergo those spontaneous changes of form
characteristic of protoplasm. On the other hand, the contents of the
larger spherical glands often separated into small hyaline globules or
irregularly shaped masses, which changed their forms very slowly and
ultimately coalesced, forming a central shrunken mass. Whatever may be
the nature of the contents of the several kinds of glands, after they
have been acted on by foul water or by one of the nitrogenous
solutions, it is probable that the matter thus generated is of service
to the plant, and is ultimately transferred to other parts.
The glands apparently absorb more quickly than do the quadrifid and
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