Chap. IV. SAPINDACE^. 151 



The two or three upper intemodes, whilst young, 

 steadily revolve ; those on one plant made two circles, 

 against the course of the sun, in 3hrs. 12 m.; in a 

 second plant the same course was followed, and the 

 two circles were completed in 3 hrs. 41 m. ; in a third 

 plant, the intemodes followed the sun and made two 

 circles in 3 hrs. 47 m. The average rate of these six 

 revolutions was 1 hr. 46 m. The stem shows no 

 tendency to twine spirally round a support ; but the 

 allied tendril-bearing genus Paullinia is said (Mohl, p. 

 4) to be a twiner. The flower-pedimcles, which stand 

 up above the end of the shoot, are carried round and 

 round by the revolving movement of the intemodes ; 

 and when the stem is securely tied, the long and 

 thin flower-peduncles themselves are seen to be in 

 continued and sometimes rapid movement from side 

 to side. They sweep a wide space, but only occasion- 

 ally revolve in a regular elliptical course. By the 

 combined movements of the intemodes and peduncles, 

 one of the two short hooked tendrils, sooner or later, 

 catches hold of some twig or branch, and then it curls 

 round and securely grasps it. These tendrils are, how- 

 ever, but slightly sensitive ; for by rubbing their under 

 surface only a slight movement is slowly produced. 

 I hooked a tendril on to a twig ; and in 1 hr. 45 m. it 

 was curved considerably inwards; in 2 hrs. 30m. it 

 formed a ring ; and in from 5 to 6 hours from being 

 first hooked, it closely grasped the stick. A second 

 tendril acted at nearly the same rate ; but I observed 

 one that took 24 hours before it curled twice round a 



