14 
or binds them in a closer cell. All this comes generally under an enquiry 
into the mode of formation of the crust of the earth, yet it involves the 
history of the changes, and when we come to many rocks, such as coal and 
chalk, we have to call in others than the mineralogist, the chemist, and the 
physicist. 
There is another path by which we may ae the subject. I will 
draw my illustration from nearer home. Suppose we travel away north, far 
beyond the boundary of the red rocks of Chester, to the borders of the lake 
country, where great masses of limestone that we know pass under all these 
rocks of Chester, are lifted up high above the sea, and carved out into valley 
and plain right down to the bottom, so that we can see what they are through- 
out, and what they, in their turn, rest upon. There are many ages—many 
geological periods older than the Righi rocks— older than the ancient Alps, 
round which the Righi rocks were formed as a shingle beach; but in that 
very ancient time the lake mountains stood—perhaps as an island in the 
sea; at any rate, the part I am alluding tu was the shore of a sinking sand, 
and along that shore, here and there, deep shingle was formed. You see it 
up the Lune valley—you see some of it left now in a great hill called Mell 
Fell, at the foot of Ullswater. Let us get some pebbles out of it. We 
might carry on the same enquiry as before in the case of the Alpine pebble 
beds, but now we will look at another point. We break our pebble open 
and a shell is seen; the shell was clearly not a shell thrown up by the 
water among the pebbles of the shore, but was in the rock from which the 
piece of stone fell that got rolled into a pebble. We find plenty of shells 
in the Jimestone that was formed on the shingle, or on the base rock, where 
the shingle would not lodge; but they are all different from the shell in the 
pebble. So we search the rocks which must have formed the old land 
round the shore of which the shingle was gathered, and in bands in that 
old rock we find the same kind of shell as that in our pebble. So we get 
at once a suggestion of the truth, worked out through ten thousand other 
examples, that at different periods of the earth's history there were succes- 
sively in any one area different forms of life, both animal and vegetable, 
and we have to return to the zoologist, and ask him what creature of to-day 
is most like the ancient form of which we show him a bone ora shell. We 
appeal to the botanist to tell us what conditions we may suppose the 
cycads and club mosses of old required. Yet this is not all. We have 
to enquire, Why did the old races perish, and whence come the new? We 
haye to ask the physiologist and biologist about the beginnings of life, and 
soon find ourselves face to face with the great problem of evolution. It 
will be seen that we have appealed already to three of the sections into 
which you haye divided your Society—to the botanist, the zoologist, and the 
physicist—for a solution of some of the problems which are brought 
before the students in the fourth section, geology. Of course we all know 
how necessary for geology is the careful study of fossil plants, and how, for 
classification purposes, the palzeobotanist has often to depend upon. quite 
different parts of the plant from those selected by the modern botanist; but 
I would offer, for the consideration of the botanists, one particular case 
which has come under my own notice, to show how strangely little bits ‘of 
