Nevertheless, the glands of Drosophyllum, without being stimulated,
continually secrete, so as to replace the loss by evaporation. Thus
when a plant was placed under a small bell-glass with its inner surface
and support thoroughly wetted, there was no loss by evaporation, and so
much [page 336] secretion was accumulated in the course of a day that
it ran down the tentacles and covered large spaces of the leaves.
The glands to which the above named nitrogenous substances and liquids
were given did not, as just stated, secrete more copiously; on the
contrary, they absorbed their own drops of secretion with surprising
quickness. Bits of damp fibrin were placed on five glands, and when
they were looked at after an interval of 1 hr. 12 m., the fibrin was
almost dry, the secretion having been all absorbed. So it was with
three cubes of albumen after 1 hr. 19 m., and with four other cubes,
though these latter were not looked at until 2 hrs. 15 m. had elapsed.
The same result followed in between 1 hr. 15 m. and 1 hr. 30 m. when
particles both of cartilage and meat were placed on several glands.
Lastly, a minute drop (about 1/20 of a minim) of a solution of one part
of nitrate of ammonia to 146 of water was distributed between the
secretion surrounding three glands, so that the amount of fluid
surrounding each was slightly increased; yet when looked at after 2
hrs., all three were dry. On the other hand, seven particles of glass
and three of coal-cinders, of nearly the same size as those of the
above named organic substances, were placed on ten glands; some of them
being observed for 18 hrs., and others for two or three days; but there
was not the least sign of the secretion being absorbed. Hence, in the
former cases, the absorption of the secretion must have been due to the
presence of some nitrogenous matter, which was either already soluble
or was rendered so by the secretion. As the fibrin was pure, and had
been well washed in distilled water after being kept in glycerine, and
as the cartilage had been soaked in water, I suspect that these
substances must [page 337] have been slightly acted on and rendered
soluble within the above stated short periods.
The glands have not only the power of rapid absorption, but likewise of
secreting again quickly; and this latter habit has perhaps been gained,
inasmuch as insects, if they touch the glands, generally withdraw the
drops of secretion, which have to be restored. The exact period of
re-secretion was recorded in only a few cases. The glands on which bits
of meat were placed, and which were nearly dry after about 1 hr. 30 m.,
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