OF THE ANNULOSA. 405 



but, in order that those analogical principles, which may 

 have served so well to connect Vertebrated animals to- 

 gether, may be transferred to the arrangement of the mul- 

 titude of heterogeneous forms which are included under 

 the comprehensive title of Animals without Vertebra,. 

 Now, on looking at the circle of Fertebrata, undoubt- 

 edly the first and most general idea we can obtain of them 

 is afforded by that bony articulated axis which gives sup- 

 port to their whole body. Our second and much less 

 general notion of them arises from the principal bony and 

 articulated appendages which are attached to this axis. 

 Every Vertebrated animal may, for instance, be consi- 

 dered as a quadruped, or at least as tending to have four 

 appendages to the vertebral column, which, whether mo- 

 dified into hands, feet, wings, or fins, are always in some 

 degree referable to one general model for their structure. 

 Man has usually been accounted to be this model; but 

 the great aim of Geoffroy St. Hilaire, in his Philosophic 

 Anatomique, is to show that every tribe of Vertebrated 

 animals, perhaps every species, has some organ or some 

 portion of an organ in a maximum state of developement, 

 and consequently that the model to which we ought to re- 

 fer every vertebrated structure is not a real existence, but 

 an abstract idea made up of all the various excellencies 

 that may be dispersed throughout the group. One being 

 may indeed come nearer to this perfect model than an- 

 other, by possessing more of these perfections ; yet, on 

 the other hand, not only is there no being in the group 

 absolutely destitute of all these characters of the model,, 

 but there is every probability also that there is no being 

 which has not some advantage of structure to boast over 

 every one of its fellow species. 



