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The leaflets began to go to sleep a
little after 6 P.M., and by 7.15 P.M. hung vertically down and were
completely asleep; but on both nights they continued to move from 7.15 P.M.
to 10.40 and 10.50 P.M., quite as much as during the day; and this was the
point which we wished to ascertain. We see in the figure that the great
sinking movement late in the evening does not differ essentially from the
circumnutation during the day.
Glycine hispida (Tribe 8).--The three leaflets sink vertically down at
night.
Erythrina (Tribe 8).--Five species were observed, and the leaflets of all
sank vertically down at night; with E. caffra and with a second unnamed
species, the petioles at the same time rose slightly. The movements of the
terminal leaflet of E. crista-galli (with the main petiole secured to a
stick) were traced from 6.40 A.M. June 8th, to 8 A.M. on the 10th. In order
to observe the nyctitropic movements of this plant, it is necessary that it
should have grown in a warm greenhouse, for out of doors in our climate it
does not sleep. We see in the tracing (Fig.


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