PREFACE. V 



dred and thirty in number) are given in an Alphabetical List of Authors 

 at the end. 



While, therefore, the book is designed primarily as a guide for beginners, 

 certain features — the references and the suggestions as to lines of inquiry — 

 may prove useful to teachers and others who may undertake to add to 

 existing knowledge. 



Histological facts and methods do not come within the scope of the work, 

 but at the close of the discussion of most of the organs is given a summary 

 of (A) the obvious or macroscopic structure — that which may be determined 

 with the unaided eye, and (B) the fine or microscopic structure. The latter 

 is in no sense complete. It embraces only the points upon which most 

 standard authors are agreed and which may be demonstrated without a 

 great expenditure of time. Only the structure of the given tissue is con- 

 sidered ; hence the presence of vessels and nerves is not mentioned. If it 

 be desired to carry the histological inquiry farther, the works of Quain, 

 Strieker, Eanvier, Beale, Frey, and the special papers therein referred to, are 

 recommended. 



Among the many friends who have aided or encouraged us, our thanks 

 are especially due to Professor Oliver Wendell Holmes for helpful criticism 

 of the terminology and for suggesting the preparation of a manual in which 

 it should be incorporated ; to our colleague, Professor J. H. Comstock, and to 

 Professors E. C. Spitzka and T. B. Stowell for valuable suggestions and 

 for the adoption in their writings of the descriptive terms herein employed ; 

 also to the last named for a critical revision of the early manuscript of the 

 muscles, and for the important additions to knowledge contained in his 

 recent paper on the vagus nerve of the cat. To all of our laboratory stu- 

 dents we are indebted for aid, suggestions and criticisms, and especially to 

 those (see end of Bibliography) who have selected parts of the cat as subjects 

 of their graduation theses. 



Our acknowledgments are here made to the American Philosophical 

 Society for the use of the four lithographic plates, and to the firms named 

 in the List of Illustrations for the courteous loan of electrotypes of instru- 

 ments manufactured by them. 



The original figures were drawn by the persons named in the Note pre- 

 ceding the List of Illustrations. The three ladies have also been our stu- 



