114 Scientific Reviews. 



Where M. Cuvi«r believes the chain to be broken, M. GeofFrojr 

 finds always the same relations, but more difficult to be seized. 



But this is not all. The elements upon which M. GeofFroy thinks 

 that the resemblances of organization ought to be established are al- 

 together different from those which have been elsewhere adopted : 

 the forms of parts and their functions have been with others the es- 

 pecial objects of examination. Hence it resulted that the veteri- 

 nary surgeons, the ichthyologists, indeed all those who treat of par- 

 ticular animals, constantly make use of different language, under 

 the supposition that they are occupied with organs peculiar to the 

 animals which are the objects of their study. 



Every one knows that things were in this state when M. Geof- 

 froy St. Hilaire proclaimed a principle, which far from enlarging 

 the received bases of zoology, far from confirming or perfecting the 

 received opinions, tended to their entire overthrow. This principle 

 consisted, in short, in the total rejection of every deduction drawn 

 from the consideration of forms and functions, and in regarding 

 anatomy as the only true foundation of all zoological research. 

 Form, said he, is fugitive from one animal to another, and functions 

 are no less so, since they increase with the bulk, whilst all other 

 things remain the same in the animal which undergoes this change. 

 IVIan, at his birth, has the same parts as the adult ; what a dif- 

 ference, however, in the functions which these parts fulfil ! Let us 

 give another more striking example, which will show how accurately 

 it may be said that there is a unity of composition in certain parts 

 which exist under very varied forms, and perform different func- 

 tions. The composition of the lower part of the anterior limb 

 of the mammalia is regarded as identical in the theory of analogies : 

 a similar use for the phalanges, the same arrangement, the same 

 disposition to form fingers, the same muscular apparatus to extend 

 and bend them ; " why, then," said M. Geoffroy, " may we not say 

 that there is an uniform repetition of materials ? why may we not 

 <sill it ' unity of composition ?' " Observe, however, how the func- 

 tion varies ; for this same trunk of the anterior limb becomes the 

 foot of the dog, the claw of the cat, the hand of the ape, a wing in 

 the bat, an oar in the seal ; and, lastly, a part of the leg in the ru- 

 minants. 



The theory of analogies differs, then, essentially from the Aris- 

 totelian doctrine, in recognizing peculiar principles, and in intro- 

 ducing into the study of organic systems anatomical considerations 

 as the only groundwork of a truly scientific classification. It has 

 not enlarged the base on which zoology rested ; it has not augment- 

 ed the resources for classification which science possessed, since in- 

 stead of admitting three elements, it considers one alone, regarding 

 it sufficient to establish identity when the examination of form and 

 function led to nothing but difference and opposition. It recog- 

 nizes other principles ; for it does not draw its analogies from the 

 organs in their totality, (which is only to be found analogous in 

 very similar ainmals), but from the materials of which the organs 

 are composed. 



