PREFACE 



Under its eminent Trustees, the Ciba Foundation is en- 

 gaged in a number of activities, all with the purpose of im- 

 proving co-operation in medical and chemical research between 

 workers in different countries and different disciplines. 

 At its house in London the Foundation provides accom- 

 modation for scientists, organizes conferences, conducts a 

 medical postgraduate exchange scheme between Great Britain 

 and France, arranges a variety of informal discussions, awards 

 two annual lectureships, is building up a library service in 

 special fields including a section on gerontology, and assists in- 

 ternational congresses and scientific institutions and societies. 



In 1954 the Trustees of the Ciba Foundation decided upon 

 special measures for the encouragement of laboratory and 

 clinical investigations relative to the problems of ageing. 

 Three conferences have been organized with this particular 

 aim in view. Two earlier ones, already published, were on 

 "General Aspects of Ageing" and "Ageing in Transient 

 Tissues". This volume contains the proceedings of the third 

 colloquium in this series — the Foundation arbitrarily uses the 

 word "colloquium" for one in a series of conferences in the 

 same field, and "symposium" for single conferences on 

 isolated subjects. On this third occasion, knowing that many 

 long-term schemes for the observation of changes with age in 

 man and whole animals were under way or about to begin in 

 various centres, it was thought useful to examine the method- 

 ology of such investigations. 



In the organization of the colloquium, the Director received 

 much kindly advice and assistance from Professor Tunbridge 

 and from Professor Best, who also acted as its Chairman. 



The reader must judge for himself the adequacy in scope 

 and technique with which these problems are being tackled. 

 It is hoped that his interest will be stimulated, his curiosity 

 aroused and his own potentialities for research challenged by 

 these comparatively informal, thoughtful discussions. 



