124 TTTP! fUTTS-ES OP *TJTf!TTTATTON'S IN TTTRGESCENCE IN THE MOTOR 



are not mechanically produced by the 

 adjoining pinnules; but there is no or 

 determined. 



of neighbouring parts, as in the case of 



pecific apparatus by which 



eh fluctuation 



are 



Movements may be induced by the action of three distinct factors: by flu 



the osmotic capacity of the 



of the motor organs, by fluctuations in the con- 



ditions affecting processes of local filtration within the motor organs, and finally, by fluc- 

 tuations in the conditions of general supply and loss of water. The normal periodic 



of 



exposure 



the movements 



or 



nyctitropic movements of the leaves, or those arising under the influence 



anaesthetics, are determined by the action of the first of these factors; 



following contact are primarily determined by the second; those following 



heating of the axis, or those attending excessive transpiration by the third. We have thus 



to deal with three distinct classes of movements in so far as their causation is concerned, 



and it is only in connection with one 



of these that phenomena of propagation manifest 



emselves. The effects of anaesthetics or of partial dep 



of light are 



ctly 



localised to the areas directly subjected to the abnormal conditions, and within which 



dep 



of functional activity 



d consequently of osmotic property 



takes 



Movements induced by local inc 

 equally unattended by any diff 



filtration, where th 



comes into play, are 



It 



nly where, and only so far 



conditions 



affecting the relations of general supply and loss of water are present that any pro- 



pagation of movement 



and, finally, it is only when and so far as such conditions 



effect negative fluctuations in the supply of water available for the maintenance of 



they 



efficient 



giving 



propagation of movements 







E. J". H— Reg. No. 6466J -320 -18-12 94. 





















