788 CARL GEGENBAUR. 



iDCthocl can be dispensed with in other --scientific researches. In itself 

 comparative anatoni}^ is only the development of methodical com- 

 parison. 1\) this end anatomy offers an experimental basis. There- 

 fore the significance of the metliod goes hand in hand Avith the al)ility 

 to apply it as rigorously as possible. This is accomplished by taking 

 into consideration all characteristics and their logical value. If this 

 be not done, the method is uncritical and therefore unscientific." 



Gegenbaur often discussed this matter, and stated in the intro- 

 duction to his most important treatise, " The Cranial Skeleton of 

 )Selachians " (German), that in this critical examination and valua- 

 tion of anatomical facts there was little in harmony Avith many 

 other contemporary endeavors, which not only assumed the accept- 

 ance of isolated occurrences as scientific j^roofs, but also regarded 

 every synthetical process of reasoning as erroneous. 



At the time, this complaint may have had a certain warrant, for 

 during the last three decades the value of the comparative anatom- 

 ical method lias not only been universally recognized, but it has 

 also been applied in many directions in anatomical and embryo- 

 logical researches. 



The series of comprehensive monographs published by Gegenbaur 

 from 1864 to 1892 constitutes the foundation for a critical comparative 

 anatomical method based on an immense amount of material. The 

 most important of these, beyond (juestion. is the monograph on the 

 Cranial Skeleton of the Selachians, published in 1872, a treatise 

 on our knowledge of the relationships of the schools of the A'er- 

 tebrates. The Avell-known vertebral theory advanced by Oken and 

 Goethe, which Avas no longer defensible in its earlier form, is here 

 revised and enlarged into a comprehensive segment theory concern- 

 ing the head of the A'ertebrate applicable to different organic 

 systems. 



In a similar manner Gegenbaur worked out from the beginning 

 almost the entire morphology of the vertebrate skeleton, in his 

 Observations on the ComparatiA^e Anatomy of the Vertebrate Col- 

 unms in Am]>hibians and Reptiles (18G2), in his paper on Carpus 

 and Tarsus (1804), on the Shoulder Girdle (18G5)-, and on the 

 Occipital Region of Fishes (1887). He had mastered also, as no 

 other naturalist, the material relating to the subject of A'ertebrate 

 morphology, and he imparted this knowledge in many unsurpassed 

 text-books prepared and published by him: in his Elements of Com- 

 parative Anatomy, Avhich first appeared in 1850, of Avhich a second 

 edition Avas issued in 1870, and Avhich Avas later published in a con- 

 densed form, in 1874, as the Fundamental Principles of Comparative 

 Anatomy (second edition, 1878) : and finally, in his most important 

 text -book, Avhich embraced his further studies for ten years and rep- 



