EFFECT OF ETHER 45 



application of ether the growth-rate became very greatly 

 enhanced in less than 15 seconds and this persisted for 

 a considerable length of time, as shown by the erection 

 of the curve and wider spacings between the successive 

 dots (fig. 19, a). Prolonged application of ether, however, 



Fig. 19. Effect of vapour of Ether on growth. 



a, enhancement of the rate (\A'heat seedhng) ; b, enhancement 

 followed by depression (Crinum) ; c, renewal of growth of 

 stem in a state of standstill (Helianthus). 



subsequently caused a depression of the rate, not shown in 

 the record. 



Experiment 17. Crinum Lily. — The result was similar 

 to that obtained with the seedling of Wheat. The accelera- 

 tion occurred within 30 seconds of the application of ether 

 vapour ; the enhanced rate persisted for a period of more 

 than 2 minutes, after which the depressing effect of pro- 

 longed application is shown, the response curve (fig. 19, h) 

 tending to become horizontal. 



Experiment 18. Stem of Helianthus. — As the cut 



