A PRETTY LAND-SHELL. 175 



of elegans. It is big enough for anybody to 

 notice it, being about the size of a peri- 

 winkle ; and its exquisite stippled chasing is 

 strongly marked enough to be perfectly 

 visible to the naked eye. But besides its 

 beauty, the cyclostoma has a strong claim 

 upon our attention because of its curious 

 history. 



Long ago, in the infantile days of evo- 

 lutionism, I often wondered why people made 

 collections on such an irrational plan. They 

 always try to get what they call the most 

 typical specimens, and reject all those which 

 are doubtful or intermediate. Hence the 

 dogma of the fixity of species becomes all the 

 more firmly settled in their minds, because 

 they never attend to the existing links which 

 still so largely bridge over the artificial gaps 

 created by our nomenclature between kind 

 and kind. I went to work on the opposite 

 plan, collecting all those aberrant individuals 

 which most diverged from the specific type. 

 In this way I managed to make some series 



