CIBA FOUNDATION 

 COLLOQUIA ON AGEING 



VOLUME 5 

 The Lifespan of Animals 



Editors for the Ctha "Foundation 



G. E. W. WOLSTENHOLME, O.B.E., M.A., M.B., M.R.C.P. 



and 

 MAEVE O'CONNOR, BjV. 



■<(. 



C^ 



With 58 niustratioiis 

 and Cumulative Index to Volumes 1-5 



LITTLE, BROWN AND COMPANY 



BOSTON 



