284 



rever.-e of the movement of the hands of ;i watch. Viewed from the side, the wind- 

 ings ascend the support from the left below to the right above (Fig. 228). Di.x- 

 TKOKSE stem-climbers .with windings from east to west occur less fre<[iiently (Hop, 

 Honeysuckle, Polii<j<nini<i cmu-ofm/iis, etc.). In the example chosen for illustrati<m 

 (Mi/r.-i/p/ii/lliim <isi>n,-ij<>i<lrs, Fig. 229) the undeveloped condition of the lateral 

 members in comparison with the elongated internodes of the stem is very apparent. 

 A very few plants, such as Blwntnbtuhia lateritia, Jlil/lii /// i/i/i/n/'i, and Sci/~ 

 . si-cm able to climb equally well either to the right or to the left. A 



I 



Fi<;. -22s. A siniatrorM stem-cumber, 



I'lmrbiti* lii*jiiila. Tin- upper 

 leaves remain small for a lon^ 



Ik 



.. _'_".'. A dextrorse stcin-c-liiiilii-i-. 

 Myi-xilihyllii'iii ti&paranniilr-<. Tin- 

 short lateral slioots liavi- de- 

 veloped phyllocladia. 



similar irregularity is shown in Solanuai dulcamara, \\liich, however, rarely 

 twines, and then only under special circumstances. 



When the apex of a sinistrorse shoot points towards the north, it is the growth 

 of the east side which is promoted by geotropism ; in dextrorse climbers, on the 

 contrary, the growth of the west side is more rapid. From the fact that the 

 promotion of growth occurs always on the same side, it will be apparent that the 

 apex of an inverted twining stem must unwind from its support ( 8T ). (Concerning 

 the behaviour of stem-climbers on the klinostat compare p. 287). 



Curvature of Grass - Haulms. All the examples of geotropic movements, so 



