8 MAMMALIA. 



"We shall then studj^ the Marsupials, an anomaly of organization 

 which is quite peculiar to them. Their young, instead of bemg 

 born in the perfect state, as with the rest of the Mammalia, come 

 into the world, if we may use the expression, unfinished, and are 

 kept by the mother in a special pouch, until their more complete 

 development is attained. 



After this order of abnormal Mammalia, will come an order 

 which also presents considerable anomaly of organization — we mean 

 the marine Mammalia, or Cetacea. Diiferent from the majority 

 of the Mammalia, in that the Cetacea are nearly all aquatic, and 

 in the A^Hiale, the Cachalot {Physeter), &c., the superior and inferior 

 members are modified in such a manner as to remind one in no 

 resi^ect of the disposition of the members in other Mammalia. 

 All of these singularities of structure justify us in giving them 

 the place we do in the order of our distribution, which is founded 

 on the increasing state of perfection of their organization. 



After the marine Mammalia, we place the Ami^hibia, which 

 present the peculiarity of being constituted with a view to their 

 double existence on land and in the water. 



After this series of what we may call abnormal orders of 

 Mammalia, we pass on to the Mammalia of a more regular 

 organization, but which are yet far from realizing all of the 

 disj)Ositions of the structure of the superior Mammalia : we 

 allude to the Pochydermata and the Ruminantia, which are so far 

 wanting in the sense of touch, that the principal organ of this 

 sense, that is to saj^, the extremitj^ of the members, is often partly 

 enclosed in a horny casing, called t/ie hoof. 



With the Pachydermata and the Puminantia, we enter into a 

 plan of organic structure already brought to a state of high perfec- 

 tion, and this character is still more marked as we advance in the 

 study of the rest of the Mammalia. The Edentata are those 

 singular creatures, designated by the name of Sloths {Bradi/pus) 

 and Armadillos {Dast/piis), whose characteristic is the absence of 

 the incisive teeth, and which sometimes have their bodies covered 

 with scaly plates. But the Carnivora, the Eodentia, the In- 

 sectivora, and even the Cheiroptera, jjresent no longer any anomah' 

 of organization, and answer exactly to the tj^pe, which we mav 

 call normal, representing this class of animals. 



The last order of Mammalia, the Quadrumtma, contains 



