594 



Marvels of the Universe 



most distill!^ uishing featuj^e of the Sensitive Plant is, of course, its habit of responding at once to 

 any touch or injur}-. Should one of the leaf-tips be knocked never so lightly, the changes start 

 to take place almost immediately. One by one the little leaflets begin to close up, next the 

 secondary stalks bearing the leaf di\'isions fall downwards, and finally the main stalk collapses with 

 a sudden jerk. It is more than likely that the leaves above the one which has been touched will 

 also show signs of having received the shock. This is a very singular outcome, and one which 

 seems to show that in its powers of shock transmission the Sensitive Plant has something which is 

 not altogether unlike the nervous system of an animal. A sudden smart tap at the base of the stem 

 of a plant brings about the collapse of the whole of the foliage. 



Now our knowledge of the causes underlying these responsive movements on the part of the 



RING. 



MusKroom. better I;no\vn to epicures by i 

 tKe taller grass, so that it is difficult to 



ns 



French 

 btain a 



Photo ty] 



X BIT OH A FAIR'l 

 Here is shown a small portion of a ring made by the true Fairy R 

 name. Champignon. Owing to their small size they are partly hidden b: 

 photograph of the whole ring. 



Sensitive Plant is not by any means complete. It is certani, however, that the collapse of the stalks 

 is due to changes in the distribution of water contained in the thickened part at the base of the 

 leaf-stalk. In its normal condition the lower part of this process is distended in such a way that 

 complete support is given to the stalk. After the reception of a shock the water passes from the 

 lower cells to other parts of the thickened portion. As a result of this a certain flabbiness arises, 

 and there is no longer the rigidity necessary to keep the leaf-stalk in an upright position. 



Most of us, as children, have wondered in a fanciful wa}' whether plants could feel pain. How- 

 ever this may be, the Sensiti\e Plant appears to be acutely conscious of things which cause suffering 

 in animals. If a lighted match be apphed to one of the leaves for only a fraction of a second, the 

 organ shrinks back as if in great pain, so that one feels that such an experiment is positively unkind ! 



