[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 8° 30' to 1° moved steadily up, with only trace a circumnutation. From 2° to 7° 20' circumnutated & I can give no explanation why geotropism failed for a time almost completely; continued rising all night, & obliquely for an 1° 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 49° above horizon. It therefore rose altogether nearly 60°— in 23° 30' other Cots within same time rose 90° 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.