Dion&a Afuscipula, HI lis. 1 1 



A leaf of the same size as the last two was acted on thus : 



i st stimulus no effect. 



2d " after forty-five seconds " 

 3d " " forty " scarcely visible effect. 



4th " " thirty " closed to about one-third. 



5th " " twenty-five" closed slowly, the movement 



occupying about thirteen 



seconds. 



Experiments were made on several large strong leaves. One 

 was sharply stimulated by pronounced bending of a hair, and 

 after lapse of forty seconds was restimulated when it closed, 

 after a movement of about three seconds. Another was 

 strongly stimulated, and restimulated after forty seconds with 

 scarcely visible effects, but after thirty-five seconds another 

 stimulus caused rapid closure. 



The above experiments were all conducted at the Edinburgh 

 Botanic Garden, in a temperature of 65 F. to 76 F., but from 

 August to October of the past year the writer experimented 

 in Washington and Philadelphia, on a liberal supply of healthy 

 plants kindly placed at his disposal by Mr. Oliver, of the 

 Washington Botanic Garden, and on three strong green plants 

 similarly provided by Prof. W. P. Wilson, of the Pennsyl- 

 vania University, Philadelphia. Recently, also, the writer had 

 the pleasure of studying Dioncea in its native haunts. The 

 plants were experimented on mostly at a temperature of 87 

 F. to 92 F. in the shade. All showed a more extended mem- 

 ory period. Thus the following cases may be selected as typ- 

 ical. A leaf was stimulated without effect, but on second 

 stimulus, after sixty seconds, it at once closed. This was fre- 

 quently verified. 



A leaf was acted on as follows : 



1st stimulus no effect. 



