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Show B4 CIRC Ul\1t.r NUTATION OF. SEEDLINGS. CHAP. I. . 24 h in Fig 24. No glass filament narrow leaf, is shown durmg .,ld· b. eneath the apex of the d b t mark was p ace was employe , u a tl Ion er of tho two ellipses do-leaf. The actual length ofut 1~14 ol an inch. On the previous scribed by the stem was abo t as nearly at right angles to h . f 1· of movemen w day the c 1e me d it was more simple. that shown in the prose?t fig)u re,;~eodlin<g was placed before a Cassia tom* (I .. egummosre · o•a.m. Cassia . t' f cotyledons and hypocotyl, traced iOI·a: conjoint Cll'cumnuta JOn o ?5th to 7 30 A.l\1. 26th. Figure on vertical glass, from 7 .I 0 A. ~1 •• se1~t. . .., 1 · here given reduced to one-half of ongmal sea e. * Seeds of this plant, which ~Jrew near the seu-side, were sent to us by Fritz 1\iiiller from S. Bmzil. TLe seedlings did not flourish or flower well with us; they were sent to 11-..ew, nn J. 11. ebro pronounced not to be distingm~ . able from C. tora. CnAr. I. L01'US. 35 north-cast window; it b nt very little towards it, as tho llypocotyl which was 1oft free was rather old, and therefore not highly heliotropic. A filament had been fixed to tho midrib of one of tho cotyledons, and tho movement of tho whole seedling was traced during two days. The circumnutation of tho hypocotyl is quito imdgnificv..nt compared with that of tho cotyledons. These rise up vertically at night and como into close contact; so that they may be said to sloop. This seedling wa::; so old that a very small trno loaf had been developed, which at night was completely hidden by tho closed cotyledons. On Sept. 24th, between 8 A.M. and 5 P.M., the cotyledons mo,rod .five times up and five times down; they therefore described five irregular ellipses in the course of the 9 h. The groat nocturnal rise commenced about 4.30 P.M. On the following morning (Sept. 25th) tho movement of the same cotyledon was again traced in tho samo manner duri11g 24 h.; and a copy of tho trncing is hero given (Fig. 25). The morning was cold, and tho window had been accidentally left open for a short time, which must have chilled the plant; and this probably prevented it fl'om moving quite as freely as on tho previous day; for it roso only four and sank only four times during the day, one of the oscillations being very small. At 7.10 A.M., when the first dot was made, the cotyledons wore not fully open or awake; they continued to open till about 9 A.M., by which time they had sunk a little beneath tho horizon : by 9.30 A.M. they had rison, and then they oscillated up and down ; Lut tho upward and downward llues never quito coincided. At about 4.30 P.l\1. tho groat nocturnal rise commenced. At 7 A.M·. on the following moming (Sept. 26th) they occupied nearly the same level as on the previous morning, as shown in tho diagram: they then began to open or sink in the usual manner. The diagram leads to the belief that tho great periodical daily rise and full docs not differ essentially, excepting in amplitude, from the oscillations during tho middle of tho clay. , Lotus Jacobreus (Lcguminosro).-Tho cotyledons of this plant, after tho few first clays of their life, 1·ise so as to stand almost, though rarely quito, vertically at night. They continue to act in this manner for a long time oven after the development of Aomo of tho true leaves. With seedlings, 3 inches in height, and bearing five or six leaves, they rose at night about 45°. They continued to act thus for about an additional fortnight. Subsequently they remained horizontal at night, though still groon, D 2 |