512 Cuviertan, or Natural, System of Zoology : — 
mal discovered in New Holland, which possesses most of the 
characters of mammiferous animals, but naturalists are not 
yet decided whether it be oviparous or viviparous. ‘This ani- 
mal is called by Blumenbach the Ornithorhyncus parad6xicus. 
Should it prove to be oviparous, it ought, says Cuvier, in 
some respects to be considered as forming a particular class. 
In the preceding description of the distinctive characters 
of mammiferous animals, it has not been deemed expedient 
to go so fully into the anatomical details as Cuvier has done ; 
what is here given will suffice to enable the student to dis- 
tineuish the animals in the different orders of this class from 
those of the three other classes of vertebrated animals. 
Division of the Class of Mammiferous Animals into Orders. 
The characters which establish the essential distinctions 
between the animals of this class, are taken from the organ of 
feeling, and the organs of mastication. On the former depend 
their different degre ees of ability or adroitness ; the latter organs 
determine the nature of their food, and are not only essentially 
connected with their digestive functions, but with numerous 
consequences relating even to their intelligence. 
The perfection of the organs of feeling is estimated by 
their number and mobility, ae by the manner in which they 
are more or less deeply covered at their extremities with nails 
or hoofs. 
A hoof which entirely covers the part of the toe that 
touches the ground, blunts the sense of feeling, and renders 
the foot incapable of seizing or grasping. The opposite ex- 
treme to this is where the eral forms a single lamina, only 
covers one side of the finger or toe, and leaves the other un- 
covered, possessing all the delicacy of feelmg of which it is 
capable. 
The regimen or nature of the food is determined by the 
form of the chewing or grinding teeth (mdcheliéres), the arti- 
culation of the jaws always depending on the form of these 
teeth. Animals that devour flesh require chewing-teeth that 
cut like a saw, and jaws restricted in their motion to opening 
and shutting like scissors. 
In order to bruise seeds or roots, it is necessary that the 
crown of the grinders should be flat, and that the jaws should 
move horizontally; it is further requisite, that the crown of 
the teeth should be always uneven, like a millstone, and that 
the substance of which it is formed should be composed of 
parts differing in hardness, that one of them may wear faster 
than the other. 
Animals with hoofs are all necessarily herbivorous, and 
