VI PREFACE. 



An experience of sixteen years as a public teacher of anatomy, 

 physiology, and surgery, has confirmed the author's conviction that 

 the only rational method of imparting a knowledge of function is 

 by associating with the latter all that is known of the forms and 

 relations of the structural elements, and of their chemical composi- 

 tion, in each part and organ. Pathological anatomy, moreover, and 

 therefore pathology, can be rationally understood only as we take 

 the same point of departure. As the student should, however, 

 study the last mentioned departments after acquiring a knowledge 

 of the healthy structure and functions, the pathological conditions 

 of the tissues are, in the present volume, specified in closer type ; 

 as intended to be more especially studied on a second reading of 

 the work. The same remark also applies to the parts which con- 

 cern the structure of the lower animals. 



Some typographical errors, overlooked in the pressure of other 

 professional occupations, will be corrected at once by the intelligent 

 reader; excepting, perhaps, those referred to at the end of the 

 volume. Some portions compiled for it, relating to pathological 

 and comparative histology, have also been omitted, to avoid render- 

 ing it formidable, from its size, to medical students ; to whom, and 

 to the profession, it is submitted as the first American work on 

 the subjects of which it treats. 



NEW YORK, October, 185T. 



