364 



Scientific Proceedings, Royal Dublin Society. 



Table III. 



Fagus siloatica. 



Similar measurements were made on the wood of Fagus silvatica. The 

 areas occupied by the various elements are recorded in Table III. The 

 percolation, or " leak," was practically the same in tlie fresh and in the 

 injected specimens, viz. 0"305 g. and 0*294 g. per sq. cm., respectively. This , 

 was not surprising, since the cylinder cut fresh from the branch was 

 moist, and sank in water. Evidently injection altered its condition but 

 slightly, since nearly all its tracheae contained water only. The velocity of 

 protoplasmic streaming necessary to overcome this " leak " is 4'656 cm.- 

 4*496 cm. per minute — a still more exorbitant demand than that of the 

 two previous determinations. 



Table IV. 



Ilex aqinfolium. 



Table lY shows the determination of the areas for Ilex aquifoUum. As 

 in the case of Fagus, the " leak " for the fresh and injected wood was 

 practically the same ; and here, again, the fresh wood was moist and sank. 

 Measurement of the amount of water which percolated through a cross- 

 section of 1 sq. cm. under unit head gave for the fresh wood 0055 g. per minute, 

 and for the injected 0-056 g. To overcome this leak a protoplasmic streaming 

 in the cells having a velocity of 1-085 cm. per minute must be admitted. 



