IN THE MOTOR OlK.ANS OF LEAVES. 



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Experiment VI. — Two leaves, weighing together 36 grammes, were set in a collecting 

 ^lass funnel over a receiver in a chloroform-chamber. On the following day they weighed 

 32*01 grammes, and a considerable quantity of a yellowish, strongly acid fluid, with a 

 specific gravity of 1030, hud accumulated in the receiver. They remained te twenty - 

 four hours longer in the chamber, and at the end of the cx]X)riinont had sustained a 

 total loss in weight of 4*86 grammes, or 13*5 per cent. 



6 ...«. „^* 6 



Experiment VII. — A large leaf, weighing %& grammes, was suspended free over a 

 collecting funnel, with a view, as far as possible, to avoid maceration of the tissues by the 

 exudation, and set in a chloroform-chamber. It showed the usual phenomena of free 

 exudation and change of colour, and ultimately lost 14*09 per cent, of its or 

 The strongly acid, yellowish fluid which collected in the receiver had a specific gravity 



of 1000. 



The amount of free exudation taking place in leaves of this plant, and probably of 



other species also, varies greatly with their age. Young leaves yield much less and 

 consequently sustain much less loss in weight than old ones, this being no doubt partly 

 due to the intercellular spaces in the former being relatively considerably larger and 

 affording more accommodation for the fluid on its escape from the interior of the cells. 



Experiment VIII. — A leaf set in an alcohol chamber began to sweat within 

 twenty-three minutes, and in the course of three hours had exuded largo pools of fluid. 

 On the following day it was of a yellowish olive colour, dryish and brittle in texture, 

 and showed a loss of 25*06 per cent, in total weight. 



B.— Bryophyllum calycinum. 



Experiment J.— A leaf, weighing 6*44 grammes, was placed in a chloroform -chamber. 

 Within the course of twenty minutes the under surface had assumed a darker green tint 

 than it had originally, due to displacement of air from the intercellular spaces and its 

 substitution by liquid escaping from the interior of the cells, and at the same time free 

 exudation appeared on the surface in the form of minute drops situated at definite points 



the margins. A little later exudation also manifested itself over the upper surface 



o tllv " o 



lly ; here, however, at no particular points, but merely showing a tendency to 

 distribution over the course of the veins. Two hours after the beginning of the experi- 

 ment, the leaf was throughout of a pale yellow colour and had lost 0*13 grammes in 

 weight. The relatively small loss of weight and the rapidity of complete discolouration 

 characterising this experiment as compared with those in which Kalanchoe leaves were 

 subjected to similar treatment are doubtless to be accounted for as the result of the 

 presence of a relatively extensive intercellular system, which on the one hand afforded 

 comparatively large accommodation for the liquid escaping from the interior of the cells, 

 and on the other brought the latter more readily into relation to the anaesthetic. 



C— Euphorbia antiquorum. 



Experiment I. — A shoot, weighing 11*26 grammes, was set in a chloroform-chamber. 

 Within an hour and a half the entire uncut surfaces came to present a peculiar greyish 

 tint due to the exudation of minute drops of latex into all the depressions in 







