PHYSIOPHILOSOPHICAL SYSTEMS. 351 



of Pander 1 upon the development of the chicken in the 

 egg, which have opened the series of those truly original 

 researches in Embryology of which Germany may justly 

 be proud, were made under the direction and with the 

 cooperation of Dollinger, and were soon followed by the 

 more extensive works of Rathke and Baer, whom the civi- 

 lized world acknowledges as the founders of modern Em- 

 bryology. 



The principles of classification propounded by K. E. von 

 Baer seem never to have been noticed by systematic 

 writers ; and yet they not only deserve the most careful 

 consideration, but it may fairly be said that no naturalist, 

 besides Cuvier, has exhibited so deep an insight into the 

 true character of a natural system, supported by such an 

 extensive acquaintance with the subject, as this great 

 embryologist has in his " Scholien und Corallarien zu der 

 Entwickelungsgeschichte des Hiilinchens in Eie." 2 These 

 principles are presented in the form of general proportions 

 rather than in the shape of a diagram with definite syste- 

 matic names ; and this may explain the neglect which it 

 has experienced on the part of those who are better satis- 

 fied with words than with thoughts. A few abstracts, 

 however, may show how richly the perusal of his work is 

 likely to reward the reader. 



The results at which K. E. von Baer had arrived by his 

 embryological investigations, respecting the fundamental 

 relations existing among animals, differed considerably 

 from the ideas then prevailing. In order, therefore, to be 

 correctly understood, he begins, with his accustomed ac- 



1 PANDER, Beitrage zur Entwicke-- flexion von Dr. Karl Ernst von Baer; 

 lungsgeschichte des Hiihnchens im Konigsberg, 1828, 4to. See also Acta 

 Eie; Wiirzburg, 1817, 1 vol. fol. Nova Acad. Leop. Caesar, vol. 13, and 



2 Ueber Eutwickelungsgeschichte Meckel's Arch., 1826. 

 der Thiere, Beobachtung und Re- 



