[5]

Oats apogeotropism

March 20 to morning of 21st

Glass-filament fixed to flat side of oldish cot, but before true leaf had had protruded; it however protruded in the evening of the same day & therefore the cot. moved less than several other in same pot. Observed at same time & same manner as Rubus. From 8º 30' to 1º moved steadily up, with only trace a circumnutation. From 2º to 7º 20' circumnutated & I can give no explanation why geotropism failed for a time almost completely; continued rising all night, & obliquely for an 1º next morning. We here have some kind of evidence of apogeotropism being modified circumnutation.

When pot was laid level cot. stood a few degrees beneath horizon & at close of observation 49º above horizon. It therefore rose altogether nearly 60º— in 23º 30' other Cots within same time rose 90º for they were in the morning parallel to earth in pot.—

(A filament was fixed to first true leaf of another seedling & this only very slightly circumnutated, rising & falling & moving laterally very slightly several times in the day; During the night rose very slightly. Therefore old cots. & first true leaf are are very little subject to apogeotropism or as we know to Heliotropism, due no doubt to growth of Cot. having occurred ceased & to growth of true leaf (authority Frank?) of Gramineæ being exclusively at base.