EDITOR'S PREFACE 



THE translation of Professor Hertwig's book Las been no easy 

 task. The extreme complexity of much of the matter treated, in 

 addition to the large number of subjects referred to, has often 

 rendered it extremely difficult to express the author's meaning in 

 readable English. Of one thing there can be no doubt, and that is, 

 that the subject matter is of very great importance ; moreover, it 

 cannot but prove most useful to the student who does not read 

 German fluently, to possess in English so comprehensive an 

 account of the Anatomy and Physiology of the Cell, as the one 

 contained in Professor Hertwig's book. 



In many cases it has been extremely difficult to find equivalents 

 for terms used in the German. Amongst these the word 

 " Anlage " may be specially mentioned. Various terms have been 

 used by different translators to express the meaning of this word, 

 but none of them seems to be applicable to all cases. Professor 

 Mark has introduced the word "fundament," and Mr. Mitchell has 

 suggested the term " blast," but neither of these appears to express 

 the meaning of the German word sufficiently accurately to justify 

 the use of either of them exclusively. Hence, we thought it best 

 in some cases to employ the somewhat cumbrous expression, 

 " elemental germ," although it is undoubtedly open to objection ; 

 however, it frequently seemed to us to convey the author's idea 

 most correctly. On other occasions we have thought better to 

 make use of a paraphrase. 



Several additions have been made to the Bibliography of papery 



