80 PEOFESSOE T. MCKENNY HUGHESj M.A. 



that species do appear under such conditions, thit we may say they have 

 been modified to suit certain laws, and that they die away when the sur- 

 roundings are unsuitable. As to the rate of modification, I will only 

 mention the change in the character of shells produced by the introduction 

 of unfavourable conditions, such as fresh or salt water, and refer to the vast 

 mass of evidence given by Darwin, iu his work on Plants and Animals 

 under Domestication. 



The meeting was then adjourned. 



