Vlii PREFACE TO THE SECOND EDITION, 



Second, the re-arrangement of the chapter on the Cranial Nerves, 

 and the introduction of some new views and facts in regard to their 

 physiology. 



Third, an account of some new experiments, original with the 

 author, relating to the function of the Cerebellum, and the conclu- 

 sions to which they lead. 



Fourth, certain considerations respecting the general properties 

 of Sensation and Motion, as resident in the nervous system, which 

 are important as an introduction to the more detailed study of 

 these functions. 



Fifth, the introduction of a chapter on Imbibition and Exhalation 

 and the functions of the Lymphatic System; including the study of 

 endosmosis and exosmosis, and their mode of action in the animal 

 frame, the experiments of Dutrochet, Chevreuil, Gosselin, Matteucci, 

 and others, on this subject, the constitution and circulation of the 

 lymph and chyle, and, finally, a quantitative estimate of the entire 

 processes of exudation and reabsorption, as taking place in the 

 living body. 



Additions have also been made, in various parts, to the chapters 

 on Secretion, Excretion, the Circulation, and the functions of the 

 Digestive Apparatus. In every instance, these alterations have 

 been incorporated with the text in such a manner as to avoid, so 

 far as possible, increasing unnecessarily the size of the book. 



Twenty-two new and original illustrations have been introduced 

 into the present volume, of which number five replace others in 

 the former edition, which were regarded as imperfect, either in 

 design or execution. The remaining seventeen are additional. 



It is hoped that the above alterations and additions will be found 

 to be improvements, and that they will enable the work, in its pre- 

 sent form, to accomplish more fully the object for which it was 

 designed. 



NEW YORK, February, 1861. 



