ACKNOWLEDGMENTS 



I AM indebted to Messrs. H. R. Bustard, R. A. Chapman and J. 

 Scholes, and to Dr. J. E. Satchell for their many helpful comments 

 and criticisms. Any faults and flaws remaining are in no way due 

 to them and I thank them for their assistance. 



Thanks are also due to the Editors and Publishers of the follow- 

 ing journals and publications for their permission to utilize figures 

 and tables reproduced in the text, and to Dr. J. N. Parle for allow- 

 ing me to reproduce the substance of a letter to Dr. J. E. Satchell. 

 Academic Royale de Belgique; Annales des Sciences Naturelles 

 Zoologie; Autralian Journal of Experimental Biology and Medical 

 Science \ Australian Journal of Science', Biochemical Journal; 

 Biochimica et Biophysica Acta; Biological Reviews; Compte 

 Rendus de la Societe de Biologic ; Gustave Fischer Verlag ; Journal 

 of Biological Chemistry ; Journal of Biophysical and Biochemical 

 Cytology; Journal of Cellular and Comparative Physiology; 

 Jourfial of Experimental Biology ; Journal of Experimental Zoology ; 

 Journal of Neurophysiology; Masson et Cie; Nature; Oxford 

 University Press; Physiological Zoology; Rockefeller Institute; 

 Unione Zoologica Italiana ; University of Chicago Press ; Wildlife 

 Society; Wistar Institute; Zoologische Jahrbiicher. Also my 

 thanks are due to Drs. J. Hanson, I. Linn and K. IVI. Rudall for 

 bringing material to my notice. 



Last but not least, my thanks go to Miss V. R. Taylor and to 

 my wife for their aid in the preparation of the manuscript for 

 publication. 



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