SENSITIVE PLANTS. 229 



■contracting from the apex towards the base as before. 

 A spray of water directed on to the leaflets caused 

 them to fall, but if not allowed to impinge directly 

 on them no motion ensued, though, of course, the 

 water did not, as the ether did, stop their mobility, 

 as a touch was sufficient to make them collapse after 

 the water spray, while after the ether spray contact 

 produced no effect." 



" The effect of the ether spray on certain other 

 plants was, in two instances, remarkable, though the 

 Tesults now to be mentioned were only obtained in 

 two instances out of many trials on various plants in 

 hot-houses in November, 1867. On applying the 

 spray to the extremity of one leaf of Iresine Herbstii, 

 which from having been grown in heat, was what 

 gardeners call ' drawn,' that is, had comparatively 

 long intervals between the leaves, and a flaccid 

 texture, a thin film of ice was speedily produced on 

 the distal end of the leaf. In less than two minutes 

 the whole shoot, four or five inches long, was ob- 

 served to bend quickly downwards. Next morning 

 the whole shoot was dead. To what precise circum- 

 stances the rapid transmission of the effect from 

 one end of the shoot to the other, and its ultimate 

 death, are due, it would be premature to assert, as it 

 is difficult in such a case to eliminate the irritant 

 effect of the ether (clearly it did not here act as an 

 anaesthetic) from the effect of the cold, and ice pro- 



