THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
35 
consumption. Now, as far as these investigations go there is. 
and in their progress it was to me a source of surprise, no 
evidence to show that this takes place. Rearrangements, 
alterations, concentration, dilution of tannin there may be, 
but they all point to the same conclusion, viz., that tannin, 
once formed, is not used up in the further processes of growth, 
except, perhaps, in the formation of resin ; and in this the 
evidence completely coincides with the non-transfer of tannin 
from falling leaves, and from the leaves of evergreens in 
winter. 
It is quite true that the general distribution of tannin in 
living tissues practically coincides with the distribution of 
starch, or of glucose; but tb : i distribution is equally com¬ 
patible with either theory, bye product or formative substance. 
Its absence from sieve-tubes is of importance in this respect, 
if, as the few notes I have bearing directly upon this lead me 
to believe it is, indeed, general. Nor is the fact that it may 
change in quantity in a particular part at different times of 
direct importance to the question, since it would be, indeed, 
remarkable were a body which exists dissolved in the cell-sap 
not to be transferable. 
Leaving on one side then the other possibilities for tannin, 
such as its relations with other secretions, or with the colours 
of plants, the possibility that by its ready oxidisability it may 
play some collateral part in plant-chemistry, or that, since it 
does not furnish a good nidus for fungoid organisms, it may 
in some way protect the dead or dying parts of the plants 
from diseases due to their attacks ; putting these on one side, 
evidence does not support the view that tannin functionates 
as a food-material analogous to starch, glucose, or oil. 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
BY BEEBY THOMPSON, F.G.S., F.C.S. 
(Continued from Vol. X., page 305.) 
How quickly would Pesults be Shown?— The effect 
produced by letting water into such a tilted triangular 
area as has been described would be most rapid at first, and 
became gradually less apparent as a larger area had to be 
filled, for at first it would not be possible to extract a large 
amount of water, and therefore more would be available for 
filling up the bed. The pressure of water, on which of course 
the yield of a well chiefly depends, would be approximately 
