Longitudinal response of radial organs 71 



The filaments of Cynerexe cannot be regarded as, strictly 

 speaking, radial organs, for their tangential diameters are 

 nearly twice as much as the radial, hence their response 

 cannot be considered as entirely unaffected by differential 

 action on the two sides. 



I shall now proceed to demonstrate that the radial organs 

 of plants exhibit response by longitudinal contraction, just as 

 muscle is seen to contract under stimulus, and that such 

 contraction, so far from being distinctive of any specific plant, 

 or of any organ of such plant, is characteristic of all radial 

 organs of plants in general. It will also be shown that the 

 lateral response of anisotropic organs is to be regarded as an 

 instance of differential longitudinal contraction. 



The Kunchangraph.— But it is here necessary to give 

 a full account of the experimental arrangements by means 

 of which this demonstration has been rendered possible, and 

 to show that the results thereby obtained are reliable, 

 consistent, and capable of the highest quantitative exactitude. 

 In this ' Kunchangraph,' ' which records the contractile response 

 of the plant, as the Myograph that of the animal, we have, 

 first, the plant chamber proper, which is made small, in order 

 that the conditions, and variations of conditions, whose effects 

 are to be studied, may be easily and rapidly changed. The 

 lower end of the organ, securely held by means of a cork, is 

 immersed in a small test-tube containing water, and fixed in 

 the middle of the base-board. The upper end of the organ 

 is connected with one arm of the Optic Lever by means of 

 a thread. The fulcrum-rod, carrying the reflecting mirror, 

 projects outside the chamber. A thin glass cylinder, not 

 shown in the figure, may be used to cover the projected 

 portion of the fulcrum-rod, thus protecting the mirror from 

 the disturbance caused by air-currents. 



One important condition which I find essential to the 

 maintenance of uniformity of sensitiveness is that the plant 

 shall be surrounded by a moist atmosphere, whose humidit)- 

 is constant. An air-bag is kept under suitable pressure, and 



' From the Sanskrit kiiiidian = contraction. The // is here pronounced as in /////. 



