[416]

Dec. 31. & Jan 1

Common Bean.

Radicle

Bean germinated on sand, turned it upside down so that radicle projected vertically up for .2 of inch in Height; fixed obliquely glass-filament to it .98 long, & traced on Horizontal glass in darkness. The tracing of bead at end of filament, magnified 22.68 times. Traced from 8°. 30' on Dec. 31 to 11° 10° Jan 1' (ie nearly 28 hours by which time radicle had increased 2-3/100 of inch in length & had begun to bow over to one side. The movement is considerable & clearly represent circumnutation. At 5° 12 began to move to left in diagram & continued so to move, but in zig-zag course till till 10° 35' P.m at night— During night it moved far in same course so as to be off glass.— Therefore at 7° a.m on Jan 1' (see tracing 1) a new tracing  begun & falling till 11° 10' & still pursued same course, but as before zig-zag, showing that apogeotropism is modified circumnutation. No doubt this movement wd have continued till end of radicle reached soil.— We Beneath soil the nutation wd be less, but I cannot doubt this movement aid in burying the radicle.—

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