204 



CIECUMNUTATION OF STEMS. CHAP. TV 



aid of their sensitive petioles, but some of them also twine 

 round supports; but even these latter species do not begin to 

 circumnutato in a conspicuous manner whilst young. The 



Fig. 72. 



Tropccolum nvtjiis (?) : circumnutation of stem of youug plant, traced on a 

 horizontal glass from 9 A.M. Dec. 26th to 10 A.M. on 27th. Movement 

 of bead magnified about 5 times, and here reduced to half of original 

 scale. 



variety here treated of has a rather thick stem, and is so dwarf 

 that apparently it does not climb in any manner. We there- 

 fore wished to ascertain whether the stem of a young plant, 



consisting of two in- 



Fi *' 73 ; temodes, together 3 '2 



inches in height, cir- 

 cumnutated. It was 

 observed during 25 h., 

 and we see in Fig. 72 

 that the stem moved in 

 a zigzag course, indicat- 

 ing circumnutation. 



(6.) 'Jrifoliitm resvpi- 

 natum (Leguminosre, 

 Fam. 75). When we 

 treat of the sleep of 

 plants, we shall see that 

 the stems in several 



, Leguminous genera, for 



Tn folium rcsnpmatum oircumnutation of . , , 



.tern, traced on vertical glass from 9.30 ^stance, those of Hedy- 



A.M. to 4.30 P.M. Nov. 3rd. Tracing not, sarum, Mimosa, Meli- 



greatly magnified, reduced to half of lotus, &C., which are not 



fromTbovt 6 ' * climbers, circumnutate 



in a con spicuoiTS manner. 



We will here give only a single instaace (Fig. 73), showing 

 the circumnntation of the stem of a large plant of a clover, 

 Trifolium resupinatum. In the course of 7 h. the stem changed 



