298 



LIFE MOVEMENTS IN PLANTS 



the organ. The extent of the maximam movement was 

 measured by the microscope micrometer. The following 

 results were obtained with four different specimens. 



TABLE XXVII. — SHOWING THE RELATIVE INTENSITIES OF RESPONSES OF THE 

 UI'l'Elt AND UNDER SIDE OK TENDRIL {Passijlora). 



It will thus be seen that the upper side of the tendril 

 is not totally inexcital)le, its power of contraction being 

 about one-seventh that of the under side. 



NEGATIVE CURVATURE OP THE TENDRIL. 



I shall now describe certain remarkable results which 

 show that under certain definite conditions the tendril 

 moves away from the stimulated side. I have explained, 

 how in growing organs the effect of unilateral stimulus 

 longitudinally transmitted, induces an expansion higher up 

 on the same side to which the stimulus is applied, re- 

 sulting in convexity and movement away from the stimulus, 

 (cf. Laws of Tropic Curvatures, p. 286). As the reaction of 

 tendril is in no way different from that of growing 

 organs in general, it occurred to me that it would be 

 possible to indue* in it a negative curvature by application 

 of indirect unilateral stimulu'^. 



