TBANSLATOB'S PREFACE. 



Tin: rapidly incivaMiii: recognition of tin- important-. OJ 

 in all iiioi-phol.^ieal studies makes it dr>iraMo t hat \ lit- mo-t val 

 text lx.>oks upon tin- -ubjeet, in whatever language, be made available 

 for those who are be^innin^its study. Although the English-ren 

 student already ha- at command a nuinher of tt-xt-books upon this 

 subject, it is evident to any one familiar with 1 1 nvwio'l 

 EntwicJdungsg&chicJtie des Menschen und der Wirl^lthiere that this 

 work covers the field of Vertebrate Embryology in a more complete 

 and satisfactory way than any book heretofore published in 



Two important objects to be accomplished in a text-book are : 

 lir.-t, a clear and methodical exposition of the well-established : 

 of the science; and, secondly, such a presentation of unset 

 question- :i> .-hall -timulate the reader to further inquiry and re- 

 search. I believe it is far too common for the second of these aims 

 to be overlooked. The present work fuliils both requirement.- i 

 eminent degree, and in its historical surveys exhibits an exceptional 

 fairness of treatment, no: withstanding the author has been one of 

 the foremost contestants in several of the fields reviewed. The 

 summai ie- which follow the discussions of the several topics serve a 

 u.-eful purpose in directing attention to the more important conclu- 

 sioii> drawn from each subject. 



I have aimed to give a c i accurate reproduction of 



author's ideas; while I have endeavored --not always successfully 

 to avoid awkward renderings and < lei-man idiom-, 1 have preferred, 

 to err on the .-ide of a too literal rather than a too liberal tran-l;r 

 There are a fen point.- that demand a brief explaiiat i.,n. The Gen 

 word .\n j 'i<i' has heretofore been variou.-ly rend* ^ r Ush 



by rnlim -lit. -// . basis, foundation, etc., while some 



writ- piising the inadequacy of any of the.-- \\-or.l- to express 



the idea, have incorporated the German word it -elf in their Knglish. 



TheJ// ; '/ : ," <-f a structure i- r ited 



state the object in a simple condition which is de-tined to be 



