SUMMARY 305 



Summary 



The geotropic reaction of a growing organ is dependent 

 on its growth-activity. In spring the latent period is 

 relatively short and the rate of erectile movement rapid. 

 In winter the latent period is prolonged and the geotropic 

 movement is very sluggish. 



The effect of chloroform in moderate dose is an enhance- 

 ment of geotropic reaction followed by arrest. Stronger 

 application produces a reversal. 



Ether, in moderate dose, induces a very marked enhance- 

 ment of geotropic reaction, the organ becoming fully erected 

 in a short time. The geotropic response of pulvinated 

 organs is also greatly enhanced under moderate application 

 of ether. 



The immediate effect of carbonic acid gas on geotropic 

 response of both growing and pulvinated organs is an 

 enhancement of the erectile movement above the normal. 

 Continued action of COg gives rise to a reversal of the 

 normal geotropic movement. 



