X^S THE HISTORY OF BIOLOGY 



particularly the bone-structure, of the vertebrates, and here he has really 

 worked out a number of ideas which foreshadow results that have been 

 gained by modern comparative anatomy. He thus derives the auditory bone 

 of mammals from the cranial bone in fishes — doubtless from the opercula 

 and not from the bones now regarded as the starting-point. He derives the 

 cartilage of the larynx from the fishes' branchial arches — as has indeed 

 been, at least partially, done in present-day comparative anatomy. But here 

 at once his unbridled imagination manifests itself in the utter lack of detailed 

 criticism and ability to limit his speculative field; thus, for instance, he finds 

 a sternum in fishes, and he derives the annular cartilages of the trachea from 

 the gill-arches, just as he delights in making direct comparisons between 

 fishes and mammals in general. (In passing, he makes the truly natural- 

 philosophical assertion that the auditory apparatus of birds is the finest 

 there is, which is proved by the fact that they are so musical.) He indulges 

 in his wildest flights of fancy, however, when he compares vertebrates and 

 invertebrates. To his mind, insects and crustaceans are composed of verte- 

 bras, in which both apophyses and ribs can be distinguished — the joints 

 are vertebrae, and the extremities ribs. The shells of the tortoise and the snail 

 are compared, and the ink-fish is a vertebrate animal with a duplication of 

 the back. One realizes that this application of the theory of a common fun- 

 damental type for the animal kingdom must have impressed Goethe. In the 

 dispute that eventually broke out between Geoffroy and Cuvier — which 

 will be described later — Goethe loyally supported Geoffroy. When Cuvier 

 died, Geoffroy was left free to promulgate his own theories, which were 

 also adopted, in part at least, by his son, Isidore, who was likewise an emi- 

 nent biologist. The more critical comparative anatomy, besides eradicating 

 the worst exaggerations, eventually acknowledged the wealth of ideas and 

 the, in many respects, productive thoughts that were to be found in Geof- 

 froy Saint-Hilaire. 



The natural-philosophical school of thought which we have endeav- 

 oured to describe above has had a deep influence on the development of bi- 

 ology. Its extravagances cannot, of course, be regarded as other than features 

 tending to retard the sound progress of science; time has also helped to put 

 them out of mind, or at worst they have been recalled only for the purpose 

 of ridiculing the weaknesses of an older generation. The service it has ren- 

 dered to humanity lies in the lively interest for the study of nature which 

 it evoked in the scientists of its era — an interest in striving to find law- 

 bound phenomena in existence. Otherwise its age certainly specialized in 

 speculation upon abstract ideas, as Hegel and his school would have it; but 

 the fact that during this period the study of nature did not disappear alto- 

 gether nor degenerate into a mere handicraft is at any rate due in no small 

 measure to natural philosophy. Many of its ideas, indeed, recur, in a more 

 or less revised form, in the biology of the nineteenth century, an account 

 of which will be given in the next section of this work. 



