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Geology. Nobody could tell what the origin of the name “ crag ” was, but 
that local name had long been applied in Norfolk and Suffolk to beds of sand 
filled more or less with beautiful fossil shells. One hundred years ago collec- 
tions from these fossils-beds were commenced. Dale, in his work on the 
Antiquities of Harwich, was the first to give us particulars of the fossils 
found in the crag ; and this formation has ever since been a favourite field for 
all who interest themselves in fossil remains. It may safely be said that there 
has been, and is still, an enormous amount of research carried on in the East 
Anglian crag. Well, forty years ago, the conclusion geologists had arrived 
at was that this Suffolk crag was rich beyond all description in the remains of 
shell and fish life generally, but that there was no trace in it of mammalian 
life. By mammalian life, I would explain that I refer to the class of animals 
commonly coming under the designation of animals which suckle their 
young, whether quadrupeds, bats, or whales — all such animals are mam- 
malian. Here let me call attention to the fact that this was negative evidence. 
I will now proceed to show how a mere accident utterly revolutionised and 
upset this negative evidence, and gave us a complete picture of a vast 
amount of mammalian life previously unsuspected. A clergyman, the Kev. 
J. S. Henslow, went one day to Felixstowe, and, while geologising among the 
crag and cliffs, came on certain dark-coloured stones, which he sent to 
London in order to have them analysed. It turned out that these stones, 
previously looked upon as worthless, contained a most valuable material 
— phosphate of lime. This led to these stones being collected in enormous 
numbers, by turning over and sifting the crag to get at them. Now, 
although during half a century scores of indefatigable geologists had been 
searching among the crag, and finding shells, corals, and fish teeth, 
but no trace of mammalian existence, no sooner did the navvies com- 
mence sifting, than out came abundant evidence of crag mammalian life, 
including mastodons, rhinoceroses, beavers, tapirs, deer, and various 
other animals belonging to the mammalian class. All this was owing 
to the mere accident of I^Ir. Henslow finding the stones I have mentioned. 
Now, supposing we were to discover in the interior of an unexplored 
part of some vast continent a lake previously unknown, and that some one 
going across in a canoe were to cast a net and draw it up, and, obtain- 
ing nothing, were to saj'’, “ I have caught nc fish ; ” what would you think 
of his logic if he were thereupon to add, “ There are no fish in this lake, 
for I have thrown my net, and drawn it up, and find it empty.” But 
that would be just as reliable evidence as you have got from the 
cretaceous rocks — in fact, it would be a parallel case to your saying, 
“ There are no remains of mammalian life in the cretaceous rocks, because 
the chalk quarries we dig and the wells we sink give us none.” This 
is a point which I would ask Mr. Callard to think well over. But, 
in saying this, I would add that, supposing there should be some day 
evidence forthcoming of land mammalian life in the cretaceous rocks, such 
evidence might not in any way support the theory of evolution. I should 
like to go on, but I fear I have detained you too long already. I may, however, 
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