vi TRANSLATOR'S PREFACE. 



Council is in no degree responsible for its tardy appearance ; 

 when, nearly three years since, the Council did me the honour 

 to accept an offer on my part to present to the Society a 

 translation of Professor Schwann's treatise, I fully hoped to 

 have proceeded with so pleasing a labour without interruption 

 or hinderance ; but various unforeseen circumstances, both of a 

 professional and domestic nature, have occurred to prevent the 

 accomplishment of my object until the present moment. 



I am greatly indebted to the Author for the labour which 

 he has expended in revising his work for this translation. 

 Amongst the most important advantages which this edition 

 has derived from his revision, I may mention the addition of 

 many notes illustrative of the text, and the amalgamation of 

 the two papers on Cartilage and Ossification, which, as they 

 were originally written and printed at a considerable interval 

 of time, led to some difficulty in the comprehension of the 

 Author's precise views on that subject ; and that circum- 

 stance is also to be received as explanatory of the appearance 

 of some of the delineations of Cartilage in Plate III. It was 

 originally intended to have added notes, which should bring 

 down the history of the subject to the period of publication, 

 but it was found that they would form a mass of material 

 almost as large as the original text, and the idea was therefore 

 abandoned. 



In order that the reader might be in possession of the whole 

 of the evidence upon which the Cell-Theory was originally 

 based, I have appended a translation of Dr. Schleiden's 

 Monograph so frequently referred to by our Author. 



