NATURAL HISTORY. 215 



" From forests, fields, from rivers, and from ponds, 

 All that have webs, or cloven-footed ones, 

 To the grand Ark together friendly cume, 

 Whose several species were too lng to name." DBAYTOW. 



tht mouth, it is ever active and watchful in determining the propel 

 (junlities of food ; and, being located near the eyes, it is instantly 

 directed to objects which they examine, and assists them in 

 discriminating the qualities of objects. 



644. How may the species of animals be determined by an 

 inspection of the detached organs ? 



It is from the correspondence between single characters and 

 general plans of structures, that the nature of the whole 

 animal is determined, from a single fragment of its skeleton, 

 or from one of its teeth. In no animal is the body made up 

 of a number of disconnected parts, united, as it were, at hazard ; 

 for all its organs have a more or less intimate connection with 

 each other, so that there is a kind of harmony amongst them all, 

 and between every part and the entire structure. 



645. Thus, the simple mspection of the 

 tooth represented in the accompanying 

 figure, suffices to disclose to the scientific 

 naturalist the following facts regarding the 

 animal to which it belonged. In tha first 

 place, there must have been a bony frame- 

 work, in which this tooth was planted, and 

 which gave support to the rest of the body ; 

 and as this internal framework does not 

 exist in any other animals than those of the 

 vertebrated series, we know that the animal 

 in question had the brain and spinal cord, 

 the complete set of organs of the senses, the 

 red blood, &c., &c., which belong to ths 

 sub-kingdom only. 



Further, there are certain characters about the roots of this tooth which enable 

 the anatomist to fee 1 certain that it must have been implanted in a deep socket, 

 which is only the case in mammals and reptiles ; and he may further determine 

 from them, that the animal belonged to the former, and that it must have, therefore, 

 possessed the organization which is peculiar to it. 



Again, by the form of the crown of the tooth, it is easily shown that it was 

 destined to divide animal flesh ; and that it consequently belonged to a carnivorous 

 quadruped. To digest the flesh, the animal must huve had a stomach and intestinal 



