PREFACE TO THE SEVENTH EDITION. 



ON no previous revision of this work has the author bestowed more 

 care than on the present. In the successive editions, it was, of course, 

 necessary to incorporate the different facts and principles, which had 

 been added from time to time, to the science ; and this rendered it 

 difficult to preserve throughout the evenness of style, which is so desir- 

 able in every treatise, and more especially in one that is placed in the 

 hands of so many of the younger portion of scientific inquirers. To 

 accomplish this object, the present edition has been subjected to an 

 entire scrutiny, not only as regards the important matters of which it 

 treats, but the language in which they are conveyed. 



Perhaps, at no time in the history of the science have observers 

 been more numerous, energetic, and discriminating than in the last 

 few years. Many modifications of fact and inference have consequently 

 taken place, which it has been necessary for the author to record, and 

 to express his views in relation thereto. Especially has he endeavoured 

 to note the phenomena that have presented themselves to the most 

 accurate observers, and to deduce from them laws which may tend to 

 enlarge the boundaries of the science : he has not, however, felt himself 

 at liberty to discard the results of the observations of all former anthro- 

 pologists, or the opinions they had embraced in regard to the various 

 functions. It not unfrequently, indeed, happens, that in ignorance of 

 the history of the science, views are esteemed new, which had been pro- 

 mulged by earlier investigators. He has, therefore, in an encyclopsediac 

 work like the present, retained many of those opinions, whilst he has 

 laboured to do especial justice to such as have emanated from more 

 recent inquirers. In this respect, his work differs from valuable phy- 

 siological treatises that are before the public. Whilst, too, he has 

 inserted the main results of the labours of recent histologists, espe- 

 cially such as are directly applicable to physiology, he has not considered 

 it advisable to pursue the subject to such an extent as if the work were 

 on general anatomy, to which histology properly belongs. 



