cease to close at night.  Those of Trichosanthes anguina are somewhat thick and fleshy, and did not rise at night; and they could perhaps hardly be expected to do so.  On the other hand, those of Acanthosicyos horrida* present nothing in their appearance opposed to their moving at night in the same manner as the preceding species; yet they did not rise up in any plain manner.  This fact leads to the belief that the nocturnal movements of the above-named species has been acquired for some special purpose, which may be to protect the young plumule from radiation, by the close contact of the whole basal portion of the two cotyledons.

Geranium rotundifolium (Geraniaceae).—­A single seedling came up accidentally in a pot, and its cotyledons were observed to bend perpendicularly downwards during several successive nights, having been horizontal at noon.  It grew into a fine plant but died before flowering:  it was sent to Kew and pronounced to be certainly a Geranium, and in all probability the above-named species.  This case is remarkable because the cotyledons of G. cinereum, Endressii, Ibericum, Richardsoni, and subcaulescens were observed during some weeks in the winter, and they did not sink, whilst those of G. Ibericum rose 27o at night.

Apium petroselinum (Umbelliferae).—­A seedling had its cotyledons (Nov. 22nd) almost fully expanded during the day; by 8.30 P.M. they had risen considerably, and at 10.30 P.M. were almost closed, their tips being only 8/100 of an inch apart.  On the following morning (23rd) the tips were 58/100 of an inch apart,

* This plant, from Dammara Land in S. Africa, is remarkable from being the one known member of the Family which is not a climber; it has been described in ‘Transact.  Linn.  Soc.,’ xxvii. p. 30. [page 305]

or more than seven times as much.  On the next night the cotyledons occupied nearly the same position as before.  On the morning of the 24th they stood horizontally, and at night were 60o above the horizon; and so it was on the night of the 25th.  But four days afterwards (on the 29th), when the seedlings were a week old, the cotyledons had ceased to rise at night to any plain degree.

Apium graveolens.—­The cotyledons at noon were horizontal, and at 10 P.M. stood at an angle of 61o above the horizon.

Lactuca scariola (Compositae).—­The cotyledons whilst young stood sub-horizontally during the day, and at night rose so as to be almost vertical, and some were quite vertical and closed; but this movement ceased when they had grown old and large, after an interval of 11 days.

Helianthus annuus (Compositae).—­This case is rather doubtful; the cotyledons rise at night, and on one occasion they stood at 73o above the horizon, so that they might then be said to have been asleep.