PKEFACE. 



IF only in the* eyes of those valued friends whose kindly interest 

 in my work has ofttimes been -as great a stimulus to sustained 

 exertion in the laborious task of translation as it has been a solace 

 in the usual and varied delays and disappointments of publishing, 

 I feel that perhaps some justification of myself is necessary for the 

 late appearance of this volume ; so much later than either they or 

 I had anticipated. The delay has in a great measure been due to 

 my being obliged to recast a large portion of my first manuscript, in 

 order to bring it down to a new and much enlarged and altered 

 Fourth Edition of the original ; commenced just as I had concluded 

 my translation more than a year ago, and the " Proofs " of which 

 I received as they were pressed off, and revised by the Author. 

 The task accomplished, however, I now feel my regret at the delay 

 lightened to a great extent by the consideration, that through it the 

 value of the work is considerably enhanced, and that the latter now 

 contains the most recently gathered matter from many important 

 fields of investigation ; passing, as it does, through the printer's 

 hands, at the same time, with the last edition of the original. 



As regards the work which I now present to my medical brethren 

 in an English dress, and which has already been translated into 

 French, any lengthy personal testimony to its value is unnecessary. 

 The fact that it now appears for the fourth time in a new edition is 

 a sufficient proof of the favour with which it is regarded as a hand- 

 book in Germany, where it was recommended to myself, when a 

 student in that country, as the best work of its kind, by one of the 

 fathers of Histology, my late valued and lamented teacher and 

 friend, Professor Max Schultze. But I am aware this translation 



