A.M. on the third morning they were nearly vertical, and again expanded during the day; on the fourth morning they were not closed, yet they opened a little in the course of the day and rose a little on the following night.  By this time a minute true leaf had become developed.  Another seedling, still older, bearing a well-developed leaf, had a sharp rigid filament affixed to one of its cotyledons (85 mm. in length), which recorded its own movements on a revolving drum with smoked paper.  The observations were made in the hot-house, where the plant had lived, so that there was no change in temperature or light.  The record commenced at 11 A.M. on February 18th; and from this hour till 3 P.M. the [page 42] cotyledon fell; it then rose rapidly till 9 P.M., then very gradually till 3 A.M.  February 19th, after which hour it sank gradually till 4.30 P.M.; but the downward movement was interrupted by one slight rise or oscillation about 1.30 P.M.  After 4.30 P.M. (19th) the cotyledon rose till 1 A.M. (in the night of February 20th) and then sank very gradually till 9.30 A.M., when our observations ceased.  The amount of movement was greater on the 18th than on the 19th or on the morning of the 20th.

Cucurbita aurantia.—­An arched hypocotyl was found buried a little beneath the surface of the soil; and in order to prevent it straightening itself quickly, when relieved from the surrounding pressure of the soil, the two legs of the arch were tied together.  The seed was then lightly covered with loose damp earth.  A filament with a bead at the end was affixed to the basal leg, the movements of which were observed during two days in the usual manner.  On the first day the arch moved in a zigzag line towards the side of the basal leg.  On the next day, by which time the dependent cotyledons had been dragged above the surface of the soil, the tied arch changed its course greatly nine times in the course of 14 ½ h.  It swept a large, extremely irregular, circular figure, returning at night to nearly the same spot whence it had started early in the morning.  The line was so strongly zigzag that it apparently represented five ellipses, with their longer axes pointing in various directions.  With respect to the periodical movements of the cotyledons, those of several young seedlings formed together at 4 P.M. an angle of about 60o, and at 10 P.M. their lower parts stood vertically and were in contact; their tips, however, as is usual in the genus, were permanently reflexed.  These cotyledons, at 7 A.M. on the following morning, were again well expanded.

Lagenaria vulgaris (var. miniature Bottle-gourd) (Cucurbitaceae).—­A seedling opened its cotyledons, the movements of which were alone observed, slightly on June 27th and closed them at night:  next day, at noon (28th), they included an angle of 53o, and at 10 P.M. they were in close contact, so that each had risen 26 1/2o.  At noon, on the 29th, they included an angle of 118o, and at 10 P.M. an angle of 54o, so each had risen 32o.