| OCR Text |
Show 220 CIRCUlVINUTATION OF STOLONS. CllAP. lV. of damp moss had emitted 2 stolons, 22 and 20 inches in length. One of these was supported, so that a length of 4~ inches ]Jrojected in a straight and horizontal line, and tho movement of the apex was traced. The :first dot was made at 9.10 A.M. ; I I I I I Fig. 89. //\"'"'"' 27~· / ' \11..a.1 J1 .. 27t.h . I 'o·ao'p.m.aorfu ~ ~-a:tp.mas<!• Cotyledon umbilicus: circum nutation of stolon, tra ced from 11.15 '\ 11 · Aug. 25th to 11 A.l\1. 27th. Plant illuminated from abore. _ 1he terminal internode was · 25 inch in length, the penultimate ~ - ~~, and the third 3 · 0 inches in length. Apex of stolon stood aL a thstance of 5 · 75 inches from the vertic;~l glass ; but it was not possible to asccrtnm how much the tracing was magnified, as it was not known how great a length of the internode circumnutated. the terminal portion soon began to bencl clownwanls and con· tinued to do so until noon. Therefore a straight lino, very nearly as long as the whole :figure here given (Fig. 89), was fu·st traced on the glass; but the upper part of this line has not _been copied in the diagram. Tho curvature occurred in tho wdclle CIIAP. IV. CIRCUMNUTATION OF S'I'OLONS. 221 of the penultimate internode; and its chief scat was at the distance of 1± inch from tho apex; it appeared due to tho weight of the terminal portion, acting on the more flexible part of the internode, and not to geotropism. The apex after thus sinking down from 9.10 A.M. to noon, moved a little to the left; it then rose up and circumnutated in a nearly vertical plane until 10.35 P.M. On the following day (26th) it was ob- Fig. 90. !f11.' a.m.2:;'!• .............. n•a.";;,";.:.,.. C0:Mla .. :m.21f1.• Cotyledon umbilicus: circumnutation and downwarJ movement of another ~olon, traced on vertic·al glass, from 9.11 A.l\1. Aug. 25th to 11 A.M. 27th. pex clos~ to glass, so that figure but little magnified, and here reduced to two-thuds of original size. ~er_ved from 6.40 A.M. to 5.20 P.M., and within this time it moved Wice up and twice down. On tho morning of the 27th the apex s!ookd as high as it did at 11.30 A.M. on tho 25th. Nor did it Sthin • down du rm. g t l1 e 28 th, but continued to circumnutate about e same place. Another stolon, which resembled the last in almost every |
