Vili PREFACE TO THE FIRST EDITION 
“Mammals Living and Extinct,’ Flower and Leydekker ; 
“Primary Factors of ‘Otgamic Evolution,” E. D. Cope; 
“Vertebrate Zoology,’ J. S. Kingsley; ‘Anatomie des 
Hundes,”” Ellenberger and Baum; “Human Physiology,” 
Schenck and Gutrber; “Osteology of the Mammalia,” 
Flower; “Human Histology,” Piersol. 
In the preparation of this book I have consulted a large 
number of works on human and comparative anatomy and 
physiology. Those giving most assistance are the works 
mentioned above, in addition to “ Mammalian Anatomy” 
by Jayne, “Anatomie Descriptive et Comparative” by 
Strauss-Durckheim, “‘ Nervése Centralorgane”’ by Edinger, 
and “Vertebrate Paleontology”? by Woodward. I am 
especially indebted to my artist, Mr. W. H. Reese, of the 
Phillipsburg High School, for the care and patience exer- 
cised in making the ceawanes from my own dissections. 
Mr. D. S. Hartline, of the Bloomsburgh State Normal 
School, has read the entire manuscript and made valuable 
criticisms. Above all, I have to thank Prof. J. S. Kingsley 
for numerous valuable suggestions and important cor- 
rections in the manuscript. 
Atvin Davison. 
