vi PREFACE 



contribute this volume to The Cambridge Manuals 

 of Science and Literature. 



If it succeeds in interesting the layman, success 

 will be due to the severe educational regime to 

 which my visitors submitted me in their cross- 

 questionings as to the bearings and objectives of 

 my biological work. 



If it fails, they must bear the blame : for had they 

 not exhibited a fondness for "Convoluta" I should 

 scarcely have ventured to publish its doings to the 

 world at large. Of these friends I would mention 

 particularly Mr Alfred Dutens, whose interest in 

 "Convoluta roscoffensis" has been a source of constant 

 encouragement to me. 



The biological facts recorded in this volume are 

 the outcome of researches carried on for some years 

 by Professor Gamble and myself, and, subsequently, 

 without Professor Gamble's co-operation. 



Throughout the whole time during which the work 

 has been in progress, it has benefited more than may 

 be stated explicitly by the unremitting assistance 

 rendered by my wife. To her, are due the long and 

 patient records of the periodic changes of behaviour 

 of the plant-animals Convoluta roscoffensis and 

 C. paradoxa : records which entailed visits to the 

 Convoluta colonies at all phases of the tide and at 

 all hours of the day and night. Though an adequate 



