194 FREAKS OF PLANT LIFE. 



interesting- facts were evolved which may be men- 

 tioned incidentally. For instance, when a revolving 

 shoot is arrested by a stick, and before it has had 

 time to make its first circle round it, the stick is 

 removed, the shoot springs forward, not perhaps to 

 catch the retreating stick, but showing that it must 

 have been pressing against it with some force. After 

 a shoot has wound itself round a stick, if the support 

 be withdrawn, the spiral will remain for a little time, 

 and then the shoot will straighten itself again, and 

 again commence revolving in search of a new support, 

 Although our indigenous twiners are able to ascend 

 by twining round a support as thin as a thread, they 

 cannot twine round an object five or six inches in 

 diameter : the honeysuckle being the only twiner 

 that will encircle trees. Exotic twiners in tropical 

 forests we know will, on the contrary, ascend large 

 forest trees. In all the examples experimented upon 

 the rotation appeared to proceed during the night 

 precisely at the same rate as during the day, showing 

 that light appears to have but little influence on 

 climbing plants. Indeed, one physiologist, Mohl, has 

 aflirmcd that twining plants are but little sensitive to 

 light. 



The conditions under which plants rotate and 

 twine most favourably, are the usual ones under 

 which they would naturally perform the other func- 

 tions of life, namely, good health and a moderate 



