Chap. X. 



APOGEOTROPISM. 



493 



Fis. 182. 



-?! 



and on the folio-wing day. During tlie second niglit it foil 

 a little, and circumnntated 

 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. 

 The stem was now inclined 

 &.r above the horizon, and had 

 therefore risen 70°- "With time 

 allowed it would jsrobably have 

 become upright, and no doubt 

 would have continued circum- 

 nutating. The solo remarkable 

 featm-e 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 

 Verbena 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 circumnntated ^'y^'SMs/rn^rans; apogeotropicroore- 

 „i- T,ii /-. i.1, r 11 • J nient of Stem from 10° beneath tr 



slightly. On the following day 



it stood upright, and circum- 

 nntated regularly, as shown in 

 fig. 82, given in the fourth 

 chapter. The stems of several 

 other plants which were highly 

 sensitive to apogeotropism rose 

 up in almost straight lines, and 



60° above horizon, traced on ver 

 tical glass, from 8.30 A.M. Ma]•<-^ 

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

 sequent circumnutating movement 

 is iiltewise shown up to 6.45 a.m. 

 on the 15th. Nocturnal course 

 repi-esented, as usual, by a broken 

 line. Movement not greatly mag- 

 nified, and tracing reduced to two- 

 thirds of oriirinal scale. 



