Ilex A quifolium, in Reference to Specific Conductivity . 543 
produces a change in the direction of the curve. This is the most marked 
in the B group. It is partly this increase in the area of the cavities which 
in some shoots causes the second ascent of Curve C ; but it does not bring 
up the average to the figure reached at the base, because, owing to the 
decrease in wood-area, the small autumn vessels close to the periphery have 
a more marked effect on the general average. It should be noticed here 
