S crN-VIXGHAM OX FLUCTUATIONS IX TURGESCEXCE. 



aooepted theory of the induction of suddenly executed movements would apparently demand, that 

 the vapour of chloroform becomes a stimulant to functional activity in a dry atmosphere, whilst it 

 act* as a depress ant in a moist one? Surely it is more rational to conclude that in both cases it acts 

 alike as a depreeient of functional activity, but that the rate at which indices to its action mani- 

 fest thei_elvee in a reduotion of turgescenoe varies with the extent to which facilities for the rapid 

 removal of water from the tissues are present. 



IV, — That the nocturnal portion of the various parts of the leaves is one which is connected with 



a degree of tunjrsceuce in the motor onjans greater than that which is present in connec- 



tion ith the diurnal position. 



* 



In order to demonstrate the groundlessness of this belief it is only necessary to call to mind the 



phenomena which can be directly observed in the guard-cells in connection with the assumption of the 



diurnal and nocturnal c .ndition by the stigmatio orifices, together with the fact that the nocturnal 



position ii ussurn.d by the lesvet of Mimotn pudica under the influenoe of ainesthelics or of conditions 



mpljing excess in transpiratory loss in relation to root-supply of water. 



APPENDIX E. 



THE IM'LULXtE OF IfVGROMETRIC COXDITIONS OX THE DEGREE OF " IRRITABILITY " OF 



MIMOSA PUDICA. 



Tiik effect of hygroraetric conditions in influencing the degree of liability to the occurrence of 

 rapid and extensively diffused movements in the leaves of Mimom pudica is illustrated by the following 

 experimental data. The experiments are arranged in two distinct groups, A and B; those included 

 under A illustrating the character and extension cf the movements following the incidence of so-called 

 '•stimulant" agencies under conditions of excessive atmospheric and telluric moisture; those under B 

 illustrating the phenomena presenting themselves under the influence of similar agencies when humidity 

 was normal or depressed. 



GROUP A. -HUMIDITY EXCESSIVE. 



a.-ZesuUs following amputation of tips of terminal pinnules of distal pinnce, or amputation 



of tips of axes, 



\. -Effects fulhwing the amputation of the tips of pinnules. 



Kxpemmknt I.- June 2%d. Ttmper.hr, 17S>F., atmospheric h u ,„id,ty 97 per cent. Sain had 



jMn ,tead.ly for mne hc m md m. Ml fallug h,„al ;/ ; even/thhg drenched Kith moutarc -Amputation 

 of the Up* of terminal pinnules was followed by a pause, duri„g whioh drops of exudation appeared at 



.he d.nded extremes of the nnd-nb and the larger veins on the out surface. Elevation of the injured 

 pmnule, o Us fellow and of one or two adjacent pairs of pinnules followed slowly. Partia l Nation 



:SX.SS;r ° rtW ° -^ * -— ^ extendld along _^. 



Experiment Il.-July 19th. Temperature $Q°F., almosnhcric h.,ml<i;tu 0.7 •> _• 



^ w *./;_ ,„.-.•„ *_ . • ,, . .. ' u,mo *P nc >w humidity Wper cent. Continuous 



f< 



fail tjenthj at the time of experiment. E\ 



ms drenched with moisture. Tae leaves «ere in mxnm.1 liurnal Litin 7 ^'""^ ^V*"* 



loaded ** adherent drops of rain. -Amputation of tn t T tf V ' ", "*"* T? ™ ^ 



slow and irregular action in a certain numbed o J^T LlZZ oTl 7, _^ ^ T 

 — , _ I A ""uie3. riequently only two or three distal pinnules 



7~ ' — ~ — ■ ■ L- 



* Sachs Ycrlesungr-n ; Voriesung, XXXII, s 789 





