Proceedings TG. 
researches of Messrs. Woodward and Kennard. There are con- 
siderable difficulties in mounting and examining the radulae of 
the smaller species, the older methods being liable to several 
serious objections; but lately I have been able to work out a 
process by which preparations of any species can safely be made. 
As in every case where comparison of many somewhat compli- 
cated objects is required, it is here of advantage to take photo- 
micrograms, which can be compared more readily than the original 
objects. In connexion with these I have had what I suppose to 
be the usual experience of photographers; one is much delighted 
with the first results; then the growth of the critical spirit pro- 
duces a very decided measure of dissatisfaction, which is only 
removed after a very careful study of the special necessities of 
the case. I need hardly add that the results of my experiments 
in mounting radulae and producing photographs of them are 
entirely at the disposal of any member of the Club who may 
desire to take up similar work. 
The Developements of Conchology to which your attention 
has now been directed have had for their object the gathering 
of evidence which bears upon the theory of Evolution. In their 
turn they involve other developements. In connexion with the 
geological view of the history of snails, we require to have the 
most precise evidence that can be obtained about the present 
distribution of the various species. Much valuable work in this 
line has been done by the Conchological Society, and especially 
by Mr. J. W. Taylor, whose Monograph of British Land and Fresh 
Water Mollusca is now being published in parts. If we know 
exactly where the different species are now to be found—and 
on this point it is to be remarked that positive evidence is more 
valuable than negative—and also know where they occur in fossil 
or sub-fossil deposits, we shall be able to form some idea of the 
migrations in which they have taken part, and Dr. Scharff has 
written an important book on this subject. This leads us to the 
the study of the dispersal of snails, the various means by which 
they have become transported from one place to another. Darwin 
himself took a considerable interest’ in this investigation, and 
Mr. Wallis Kew has contributed a suggestive treatment of it to 
the International Scientific Series. It is evident that in connexion 
