M. Agassiz on the Classification of Fishes. 135 



groups succeed each other, and in the names applied to them. 

 The most important changes effected in the general system of 

 zoology, since the time of Linnaeus, consist in the dismem- 

 berment Cuvier has made of the Swedish naturalists' shapeless 

 and undigested class of Vermes ; and it may be affirmed, with* 

 out in any dcgi'ee depreciating the value of the works of mo- 

 dern naturalists, that they are only a development of the pri- 

 mary sections of the great French naturalist. The modifica- 

 tions which these classifications have been subjected to in der 

 tail, do not appear to me less important ; but they belong to 

 so many difierent authors, that I cannot here undertake to give 

 any account of them ; I shall only say that they have essen- 

 tially borne upon defining the limits of families and genera, 

 and upon a more complete and rigorous appreciation of their 

 characters. 



But while this advancement was going on in zoology pro- 

 perly so called, a new science arose, under the hands of the 

 same individual who had already contributed so powerfully to 

 the development of zoology. The study of fossils acquired, 

 from the profound researches of Cuvier, an importance hither- 

 to unknown to it, from the time when he demonstrated that 

 the remains of organized beings embedded in the strata of the 

 earth, are generally different from the living species, and even 

 belong to different generic types. This fact having been firmly 

 established in regard to the mammifera and reptiles, investi- 

 gations were increased in all the classes, and in relation to all 

 the series of strata composing the solid crust of our globe in 

 which fossils are found. The relations of these primitive beings 

 with those which at present people the surface of the earth, 

 were inquired into ; observers were desirous to appreciate their 

 analogy, and determine the differences which distinguished 

 them. This investigation was the cause of new and great 

 progress in zoology and the comparative anatomy of the solid 

 parts of the bodies of animals ; and it is easy to see that the in- 

 fluence of paleontology on zoological and anatomical studies will 

 become more and more important in proportion as these different 

 branches of science become more closely xmited. I do not even 

 doubt but that we shall soon be led to unite the results of pan- 

 leontological and zoological researches into one body, as soon 



