350 ESSAY ON CLASSIFICATION. 



the Fishes, and the like, and yet says that Cuvier "was 

 totally unacquainted with the very first principles of the 

 natural system," hardly deserves to be studied in our 

 days. 



The attempt at representing graphically the compli- 

 cated relations which exist among animals has, however, 

 had one good result, it has checked, more and more, the 

 confidence in the uniserial arrangement of animals, and 

 led to the construction of many valuable maps exhibiting 

 the multifarious relations which natural groups, of any 

 rank, bear to one another. 



SECTION VI. 



EMBRYOLOGICAI, SYSTEMS. 



Embryology, in the form it has assumed within the last 

 fifty years, is as completely a German science as the 

 " Naturphilosophie." It awoke to this new activity con- 

 temporaneously with the development of the Philosophy 

 of Nature. It would hardly be possible to recognize the 

 leading spirit in this new development, from his published 

 works; but the man whom Pander and K. E. von Baer 

 acknowledge as their master must be considered as the 

 soul of this movement, and this man is Ignatius Dollinger. 

 It is with deep gratitude I remember, for my own part, the 

 influence which that learned and benevolent man had upon 

 my studies and early scientific application during the four 

 years I spent in his house, in Munich, from 1827 to 1831. 

 To him I am indebted for an acquaintance with what was 

 then known of the development of animals prior to the 

 publication of the great work of Baer; and from his lec- 

 tures I first learned to appreciate the importance of Em- 

 bryology to Physiology and Zoology. The investigations 



