424 



MODIFIED CIKCUMNUTATION. 



Chap. VUl 



similar to the previoiis one. In these two cases there coiild be 

 no doubt that the ordinary circumnutating movement of the 

 hypocotyl was modified and rendered heliotropio. 



Fig. 171. 



13:48' 



M'.SO\ 



fffHOn 



S-ja'am* 



m'-SO'a.m. 



Ap'os grareolens: heliotropic morernent and ciroumnutation of the hypo- 

 cotyls of two seedlings towards a dim lateral light, traced on a horizontal 

 glass during the day. The broken lines show their return nocturnal 

 courses. Height of hypocotyl of A -5, and of B -55 inch. Figure reducej 

 to one-half of original scale. ^ 



Brassica oZeroceos.— The hypocotyl of the cabbage, when not 

 Usturbed by a lateral light, circumniitates in a complicated 



