placed near the margin of a leaf, and caused in 3 hrs. 20 m. increased
secretion and incurvation. After 24 hrs. the leaf was partially
unfolded, but the glands were still secreting freely. These began to
dry in 48 hrs., and after 72 hrs. were almost dry. The two seeds were
then placed on damp sand under favourable conditions for growth; but
they never germinated, and after a time were found rotten. They had no
doubt been killed by the secretion.
(5) Small bits of a spinach leaf caused in 1 hr. 20 m. increased
secretion; and after 3 hrs. 20 m. plain incurvation of the margin. The
margin was well inflected after 9 hrs. 15 m., but after 24 hrs. was
almost fully re-expanded. The glands in contact with the spinach became
dry in 72 hrs. Bits of albumen had been placed the day before on the
opposite margin of this same leaf, as well as on that of a leaf with
cabbage seeds, and these margins remained closely inflected for 72
hrs., showing how much more enduring is the effect of albumen than of
spinach leaves or cabbage seeds .
(6) A row of small fragments of glass was laid along one margin of a
leaf; no effect was produced in 2 hrs. 10 m., but after 3 hrs. 25 m.
there seemed to be a trace of inflection, and this was distinct, though
not strongly marked, after 6 hrs. The glands in contact with the
fragments now secreted more freely than before; so that they appear to
be more easily excited by the pressure of inorganic objects than are
the glands of Pinguicula vulgaris. The above slight inflection of the
margin had not increased after 24 hrs., and the glands were now
beginning to dry. The surface of a leaf, near the midrib and towards
the base, was rubbed and scratched for some time, but no movement
ensued. The long hairs which are situated here were treated in the same
manner, with no effect. This latter trial was made because I thought
that the hairs might perhaps be sensitive to a touch, like the
filaments of Dionaea. [page 394]
(7) The flower-peduncles, sepals and petals, bear glands in general
appearance like those on the leaves. A piece of a flower-peduncle was
therefore left for 1 hr. in a solution of one part of carbonate of
ammonia to 437 of water, and this caused the glands to change from
bright pink to a dull purple colour; but their contents exhibited no
distinct aggregation. After 8 hrs. 30 m. they became colourless. Two
minute cubes of albumen were placed on the glands of a flower-peduncle,
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