UPPER AND LOWER HALVES 



337 



unjustifiable assumption that in the first case the stimulation 

 is maximal, while in the latter it is subminimal. 



The following facts are of confirmatory value. In my 

 ' Nervous Mechanism of Plants ' it has been shown that the 



Fig. 200. 



Fig. 201, 



Fig. 200. Photo-micrograph of transverse section of upper half 

 of horizontally laid stem of Impatiens. 



Note the starch-grains fallen on to the inner tangential wall of 

 statocysts s which abut on the phloem p. 



Fig. 201. Longitudinal section of upper and lower halves of 

 geotropically curved stem of Eclipta. 



Note contraction of the upper and expansion of the lower cortex 

 c. The starch-grains have fallen on the inner tangential wall 

 of the upper statocysts (abutting on the phloem p). The 

 starch-grains in the lower statocysts are lying against the 

 outer tangential wall. 



phloem functions as a nervous tissue, and it may be of 

 significance that the statocysts are situated in closest 

 contiguity with the phloem. 



Fig. 200 shows the transverse section of the upper half 



