respected authorities object to it, I was 

 sufficiently convinced of my personal 

 experience. ^ 



Baer continued his embryological investigations after 

 an interruption for vast organizational work for the 

 establishment of a zoological museum in Konigsberg. His 

 resumption of embryological work Baer credited to his 

 colleague in the University of Konigsberg, Professor Karl 

 Burdach. Burdach undertook an extensive study under the 

 title, DIE PHYSIOLOGIE ERFAHRUNGSWISSENSCHAFT 

 (1826 - 27), and he suggested that Baer include his data 

 in this work about the development of vertebrate animals. 

 Baer agreed and gave Burdach a note containing the results 

 of his investigations on frog and hen development, accom- 

 panied by a member of general considerations (91) . These 

 articles in Burdach' s manual represent the first version of 

 the UBER ENTWICKLUNGSGESCHICHTE . 



Furthermore, in his preface Baer hesitated at some terms. 

 In particular he spoke about the "embryonic membrane" (KEIMHAUT, 

 or extra- embryonic blastoderm in modern terminology) , then 

 about the terms "dorsal and abdominal plates" which have 

 significance for the comparison of vertebrate and invertebrate 

 development, and finally about the replacement of the name 

 "spinal cord" with the term "vertebral cord" in order to give 

 it a more definitive localization and embryological importance. 



Baer devoted several pages of his preface to explaining 

 that he was little concerned with the investigations of other 

 authors and referred to them only in cases of actual gaps in 

 specific data. This does not mean, however, that he under- 

 estimated the value of his predecessors such as Wolff, Oken, 

 Purkinje, and others. Detailed citations of others' works 

 could have diverted him from his own specific details and 

 systematic data, to which Baer aimed his fundamental work. 



4. K. M. Baer. UBER ENTWICKLUNGSGESCHICHTE, I, p. 12 

 (p. viii) . (Ed. : References are evidently, to the Russian 

 edition. The brackets represent pages in UBER 

 ENTWICKLUNGSGESCHICHTE (Brussels: Culture et 

 Civilisation, 1967, reprint of 1828 Konigsberg edition) . 

 Hereafter listed without further specification as (v. #, 

 section # (if any), p. #).) 



303 



