CH. VIIl] 



AVERRHOA. 



225 



(one of the Oxalida;) also drops its leaflets in sunshine 

 as it does at night. The leaves of Averrhoa, as described 

 in exp. 261, exhibit remarkable autonomous movements \ 

 in which the leaflets drop rapidly through 15^ — 20', 

 then rise slowly to their original position, repeating the 

 movement once in 15 minutes or so. When sunshine 

 strikes the plant the leaflets fall until they make an angle 

 of 70° or 80° below the horizon, but this is not effected in 

 a single drop, but by series of rapid rises and falls as 



Fig. 42. Exp. 257. From Power of Movement. 



represented in fig. 42. In this diagram the numbers 0° 

 to 60° on the left represent the angular divergence in 



1 Lynch in Linnean Soc. Journal, xvi. p. 231 ; Power of Movement in 

 Plants, p. 330. 



D. A. 



15 



