of the Peruvian Lama. 483 



laws regulating the presence or absence of organs, and sufficiently 

 accurate and extended, to enable them to decide a priori on 

 structure ; or, to state the problem in the language of the ma- 

 thematician, " from a given part of the structure, to describe the 

 whole." To me it appears that the question of organization is 

 not to be solved in this way. We may determine, by such means, 

 unknown quantities, and the greater number of questions in 

 physics and mechanics, because their laws are already so well 

 made out, that, generally speaking, there are no real exceptions 

 to these laws, and, above all, every possible combination, if I 

 may so express myself, is already known to the inquirer ; but to 

 me it seems quite different with living organized bodies. The 

 possible combinations of form have not been fully determined ; 

 exceptions which, though not real, have all the force of reality 

 until they shall be explained, are too numerous ; they exist to a 

 degree that the memory can no longer retain them, so that 

 every thing like system and general laws is lost. Let not the 

 anatomist then deceive himself and others. The high authority 

 which would persuade us, that from a small portion of bone we 

 may determine the form, the anatomy, the natural history, the 

 antiquity of an unknown animal, I altogether disregard, sup- 

 porting my seeming neglect of such well-earned reputation, by 

 the strong conviction which naturally arises in my mind, from an 

 extent of anatomical inquiry into the structure of almost every 

 kind of animal at present found to inhabit the earth's surface ; 

 an inquiry extended now to rather more than fifteen years. 



I shall bring these observations to a conclusion by remarking, 

 that the anatomy and natural history of any species of animal, 

 fully observed, and made out satisfactorily, may enable us to de- 

 cide on the anatomy and natural history of an animal unknown 

 to us, provided they accord entirely, or nearly so ; that, more es- 

 pecially in some natural families, such as the strictly carnivorous 

 tribe, a tooth, a fragment of bone, or other remains of structure, 



VOL. XI. PART II. 3 P 



