in different directions.  After 11.10 A.M. on the 12th this part of the stem, still considerably curved, circumnutated in a conspicuous manner until nearly 3 P.M. on the 13th; but during all this time a downward movement of the filament prevailed, caused by the continued straightening of the stem.  By the afternoon of the 13th, the summit, which had originally been deflected more than a right angle from the perpendicular, had grown so nearly straight that the tracing could no longer be continued on the vertical glass.  There can therefore be no doubt that the straightening of the abruptly curved portion of the growing stem of this plant, which appears to be wholly due to hyponasty, is the result of modified circumnutation.  We will only add that a filament was fixed in a different manner across the curved summit of another plant, and the same general kind of movement was observed.

Trifolium repens.—­In many, but not in all the species of Trifolium, as the separate little flowers wither, the sub-peduncles bend downwards, so as to depend parallel to the upper part of the main peduncle.  In Tr. subterraneum the main peduncle curves downwards for the sake of burying its capsules, and in this species the sub-peduncles of the separate flowers bend

* ‘Ueber Orthotrope und Plagiotrope Pflanzentheile;’ ’Arbeiten des Bot.  Inst., in Würzburg,’ Heft ii. 1879, p. 226. [page 277]

Fig. 124.  Trifolium repens:  circumnutating and epinastic movements of the sub-peduncle of a single flower, traced on a vertical glass under a skylight, in A from 11.30 A.M.  Aug. 27th to 7 A.M. 30th; in B from 7 A.M.  Aug. 30th to a little after 6 P.M.  Sept. 8th. [page 278]

upwards, so as to occupy the same position relatively to the upper part of the main peduncle as in Tr. repens.  This fact alone would render it probable that the movements of the sub-peduncles in Tr. repens were independent of geotropism.  Nevertheless, to make sure, some flower-heads were tied to little sticks upside down and others in a horizontal position; their sub-peduncles, however, all quickly curved upwards through the action of heliotropism.  We therefore protected some flower-heads, similarly secured to sticks, from the light, and although some of them rotted, many of their sub-peduncles turned very slowly from their reversed or from their horizontal positions, so as to stand in the normal manner parallel to the upper part of the main peduncle.  These facts show that the movement is independent of geotropism or apheliotropism; it must there[fore] be attributed to epinasty, which however is checked, at least as long as the flowers are young, by heliotropism.  Most of the above flowers were never fertilised owing to the exclusion of bees; they consequently withered very slowly, and the movements of the sub-peduncles were in like manner much retarded.