vi PREFACE. 



Professors Birch, Gotch, Rutherford, and Schafer, Dr Bayliss, Dr 

 Gregor Brodie, and C. Herbert Hurst, Ph.D. The sources of the 

 other illustrations and methods are acknowledged elsewhere. 



I have also to thank my pupils, Messrs Moore, Halstead, and 

 J. H. Sheldon, for some of the drawings, and my Senior 

 Demonstrator, Dr J. A. Menzies, for reading the proof sheets, and 

 for other kind assistance and suggestions. 



WILLIAM STIRLING. 



PHYSIOLOGICAL LABORATORY, OWENS COLLEGE, 

 MANCHESTER, August 1895. 



