Hazel-wood with Reference to Conductivity of Water . 563 
of an element is very small, its wall occupies a greater proportion of its total , 
area in transverse Section. The general rise in the curve up to the maximum 
is certainly due to the fact that the wood becomes richer and richer in 
vessels and poorer in fibres, as can be seen clearly from the sections. 
On the whole, the higher values for specific conductivity, curve C, in H9 
and Hio, than in H7 and H8, are associated with lower figures for the area 
Fig. 7. 
■ - 1 .. ' \ - 
of the wood, curve A ; this brings the values for total conductivity, curve B, 
nearer together in the four shoots. It means that there is a greater propor¬ 
tion of fibres in the larger wood sections. The maximum in curve C occurs 
nearer to the apex in H8 than itl the other shoots; it will be noticed also 
that at this internode, the third from the top, there is a greater area of wood 
and a greater value for total conductivity in H8 than at the corresponding 
internodes in the other shoots. This may possibly have some connexion 
with the fact that the terminal bud is present in H8. 
