14 
on the limestone rock-structure of that district. Mr. Wilmore 
exhibited several familiar scenes selected from the West 
Yorkshire Dales, such as Troller’s Gill, Malham Cove, Gordale 
Scar, and Giggleswick Scar. A very interesting study in the 
Craven limestones is in connection with the lecturer’s own 
special work in Craven, as laid before the British Association 
and the Yorkshire Geological Society. Many of the limestones 
appear quite structureless and absolutely unfossiliferous as 
seen in the ordinary way. Now, in modern research, these 
rock types are ground down until quite transparent, and may 
then be studied under the microscope. Mr. Wilmore is now 
engaged on a detailed study of a large series of these limestones 
by this method, and some of his results were shown by means 
of micro-photographic lantern slides. Another piece of work 
on which the lecturer has been engaged is the evolution of 
the various life-forms during the immense period whose 
history is contained in the Craven rocks. This evolution is 
traceable in all the types, but Mr. Wilmore has hitherto 
confined his attention to the corals and brachiopod shells. 
Some original lantern slides were shown which clearly 
demonstrated the various stages in the evolution of some 
of these forms, and which give some idea of the modifications 
due to changing environment which are seen. The lecturer 
is still at work on this subject, and hopes to lay some further 
results before the Geological Society of London and the 
British Association during the next two years. 
In reply to questions the lecturer said that in reference 
to the age of the Craven fault, Professor Tiddiman, who 
surveyed the district, believed that the Craven fault was in 
progress during the depositions of the carboniferous rocks. 
He (the lecturer) was sorry he could not subscribe to that 
opinion. Others believed it was of much more recent origin 
and was bound up with the later up-lift. They had in that 
district 2,000 feet of coal measures and many of those coal 
seams must have been deposited on the surface. The most 
difficult question was as to the reason why certain types had 
taken the privilege to live on when the host of others had had 
to give way. That involved the question of evolution and the 
survival of the fittest, on which they talked glibly, although 
they were only playing on the fringe of that great problem 
of evolution. The dolomites were much commoner in the 
Craven area than anyone would have thought. 
