PREFACE 



THE majority of the lectures and addresses col- 

 lected together in this volume have already been 

 printed in the Transactions of several Societies 

 viz., the lecture on Animal Pedigrees, published 

 in the Midland Naturalist; the Presidential address 

 to the Biological Section of the British Association ; 

 and several reprinted from the Transactions of the 

 Manchester Microscopical Society. Of these printed 

 addresses I have reproduced as many as possible 

 without involving too much repetition. In the 

 case of the British Association address however it 

 will be found that many of the points discussed 

 are dealt with in other addresses, especially in the 

 lecture on Animal Pedigrees, which is indeed based 

 on that address. It appeared however desirable 

 to include the British Association address, even 

 at the risk of repetition, on account of the im- 

 portance of its scientific value, and for this reason 

 I have placed it at the end of the series, the others 

 being arranged chronologically. 



With regard to the lectures in manuscript, 



