Chap. X. 



APOGEOTEOPISM. 



4P5 



and on the following day. Dnring tlie second night it foil 

 a little, and circnmnutated 

 during the following day ; but it 

 also moved a short distance to 

 the right, which was caused by 

 a little light having been ac- 

 cidentally admitted on this side. 

 Tb.e stem was now inclined 

 &)' above the horizon, and had 

 therefore risen 70°. With time 

 allowed it would probably have 

 become upright, and no doubt 

 would have continued circum- 

 nutating. The sole remarkable 

 feature in the figure here given 

 is the straightness of the course 

 pursued. The stem, however, 

 did not move upwards at an 

 equable rate, and it sometimes 

 stood almost or quite still. 

 Such periods probably represent 

 attempts to circumnutate in a 

 direction opposite to apogeo- 

 tropism. 



The herbaceous stem of a 

 I'erhena melindres (?) laid hori- 

 zontally, rose in 7 h. so much 

 that it could no longer be 

 observed on the vertical glass 

 which stood in front of the plant. 

 The long line which was traced 

 was almost absolutely straight. 

 After the 7 h. it still continued 



to rise, but now circnmnutated C</<'««/™3ra«s.- npogeotro,,icmove. 



merit of stem from 1U° beDe;ith t<- 



slightly. On the following day 

 it stood upright, and circnm- 

 nutated regularly, as shown in 

 Pig. 82, given in the fourth 

 chapter. The stems of several 

 other plants which were highly 

 sensitive to apogeotropism rose 

 np in almost straight lines, and 



60° above horizon, traced on ver 

 tical glass, from 8.30 A.M. March 

 12th to 10.30 P.M. 13th. The sub- 

 sequent circumnutating movement 

 is likewise shown up to 6.45 A.M. 

 on the 15th. Nocturnal course 

 represented, as ti.^ual, by a broken 

 line. Movement not greatly mag- 

 nified, and tracing reduced to two- 

 thirds of orisrinal scale. 



