THE FEELINGS OF PLANTS 



I02I 



THE TENDRILS OF THE VIRGINIAN CKEHl'KK TLKN Aa \ 



THE LIGHT. 



FROM 



of them is held outwards. It is easy to 

 understand that it is to the advantage of 

 most plants to bring their foliage into 

 such a position that a maximum amount 

 of light is secured. Movement towards 

 the light is not an invariable feature in 

 the organs above ground of all plants. 

 In the case of the l\y there is a distinct 

 tendency for the shoots to bend away 

 from the light. 



^lore strange still is the behaviour of the 

 tendrils of the \'ine and Virginian Creeper. 

 These processes always shun the brightly 

 illuminated quarters, and seek out the 

 dark parts. The phenomenon is all the 

 more remarkable when it is remembered 

 that in origin these tendrils are modified 

 leaf-shoots — portions of the plant which 

 in the ordinary way would certainly not 

 turn away from the light. That the 

 tendrils are more likely to obtain a hold 

 by directing their growth to the dark 

 cracks and crevices than if they grew out 

 to the light, is, of course, obvious. A 

 most curious instance in which the same 

 part of a plant is affected by light in 

 different ways at different times is to be 

 seen in the case of the Ivy-leaved Toad- 

 fla.x {Linaria cymbalaria) . The flower- 

 stalks at first incline towards the light, 

 but as soon as the bloss(jms ha\'e been 

 fertilised the stems turn in an opposite 



direction and so bring the capsules into 

 a position for planting the seeds in the 

 crevices. 



On occasions the foliage of the plant 

 is seen to shun the light. It is noticed 

 by all travellers that the Australian 

 forests offer very little shade ; this is 

 simply due to the fact that certain of 

 the trees (particularly the Eucalypti) 

 hold their leaves edgeways to escape 

 the fierce rays of the sun. It is curious 

 that the seedling Eucalyptus trees bear 

 their leaves laterally. Of course, these 

 young specimens growing in the partial 

 shade afforded by their parents are not 

 likely to suffer harm from the sun's rays. 

 The so-called Compass Plant (Siiphiiim) 

 has leaves which twist laterally when the 

 sun shines upon them, and in this way 

 avoid the injurious effects of too strong 

 an illumination. Many plants under the 

 intluence of very strong sunlight droop 

 their foliage ; partly, of course, because 

 of the excessive transpiration of moisture ; 

 but we may take it that the change in 

 position is a useful protective measure. 



As to the causes which underlie these 

 light -seeking and light-avoiding move- 

 ments, we cannot find any all-sutficing 

 exjilanations. Certain it is that they 

 onlv continue so long as the plant is in a 

 growing state. We know that light has 



