Pref 



ace 



I HE OBJECTIVES of comparative physiology are: (1) to describe the 

 diverse ways in which different kinds of animals meet their 

 - functional requirements; (2) to elucidate evolutionary relation- 

 ships of animals by comparing physiological and biochemical characteristics; 

 (3) to provide the physiological basis of ecology, describing the mechanisms 

 of tolerance of the stresses of particular habitats and the functional adaptations 

 underlying extension of the range of a population; (4) to call attention to 

 animal preparations particularly suitable for demonstrating specific functions; 

 and (5) to lead to broad biological generalizations arising from the use of kind 

 of animal as one experimental variable. 



The present book attempts to serve two purposes: (I) as a textbook for 

 use in courses in comparative physiology at the advanced undergraduate-early 

 graduate level by students with some background in zoology and mammalian 

 physiology; (2) as a source book of sufficient detail and bibliography adequate 

 to introduce investigators to particular branches of the subject. No attempt 

 is made to cover in detail the fields of cellular and mammalian physiology, 

 although a certain amount from each is utilized; experience favors the 

 separation of courses in comparative, cellular and mammalian physiology. 

 The index is arranged to provide zoologists with material on the physiology 

 of particular animal groups, and this book might well give the physiological 

 material for courses in invertebrate zoology, protozoology, helminthology, ento- 

 mology, ichthyology, herpetology, ornithology, and mammalogy. 



The enormous literature of comparative physiology exists mainly in journals 

 and monographs, and the only truly comprehensive account in recent years 

 is Buddenbrock's Grundriss der vergleichenden Physiologie. The bibliography 

 of the present book, although extensive, is highly selective and therefore 

 not comprehensive; it does not include many papers published since August 

 1949. No effort is made to cite the earliest reference for a given tact, but 

 rather the recent important references are cited, and interested readers can 

 trace earlier literature from these. 



Some animals are designated by two names and the same name is not 

 always used throughout the book. This results from changes in nomencla- 

 ture introduced by systematists who, for reasons of priority or reclassification 

 at the generic or specific levels, find it necessary to discard names which have 

 been used extensively in experimental papers. In this book, with a few 

 exceptions, animal names are given as used in the original experimental 



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