4 NATURAL HISTORY. 



Another peculiarity which exists in all ruminating animals is the absence of cutting-teeth in the 

 middle of the upper jaw ; and it is only in the Camels and their intimate allies, the Llamas, that there 

 are any upper cutting-teeth at all, they being replaced in all the others by a callous pad, on which the 

 lower cutting-teeth impinge in mastication. 



The canine teeth, which correspond to the tusks of the Lion and Dog, also deserve attention. 

 Those of the lower jaw are always present, and are modified so as to appear like lateral cutting- 

 teeth. In the upper jaw they are most often absent, but are enormous, projecting far down oiitside 

 the lip, in the Musk, the Chinese Water Deer, and the Muntjacs. In some other Deer they are 

 present, but small, and generally they are wanting. 



The grinders are six on each side of each jaw, and are so formed that their surfaces wear down 

 unevenly by the lateral movement to which they are subject during mastication. As in the Elephant, 

 this depends upon each tooth being made up of alternate layers of enamel, dentine, and cementum, 

 which, being of different degrees of hardness, are differently affected by the grinding action. 



The ruminating animals exhibit a fair amount of intelligence, never, however, attaining that 

 power of perception and memory exhibited by the Carnivora and other higher forms. The 

 figure of the surface of the brain of the Sheep indicates that the convolutions of the brain are far 

 from inconsiderable in number, and its allies of the same size agree with it in this respect, whilst 

 larger species have more, and smaller less elaborate brain-markings, as is nearly always found to be the 

 case in every group. 



The accompanying table gives an outline sketch of the classification of the ruminating animals 

 which has been adopted by zoologists : 



Sub-order. Section. Division. Group. 



( Ox-tribe 



HORNED RUMINANTS. 

 CHEVROTAINS OR DEER- 



RUMTNANTIA. 



Deer-tribe 



TRL-E RUMINANTS. 



LETS 



(Tragtdid(i') 





CAMEL TRIBE. 

 ( Tylopoda] . 



Tlio large sub-order of the Ruminantia is seen to be primarily divided into two sections, namely, 

 the typical Ruminants and the aberrant Ruminants (the Tylopoda). The typical Ruminants, in 

 which the stomach is formed upon the plan of that described above in the Oxen, fall into two 

 divisions, the smaller of which that of the Chevrotains or Deerlets possesses 110 psalterium, or 

 third stomach, except in a rudimentary condition. The Horned Ruminants, including the Deer, 

 Muntjacs, Elk, Oxen, and Antelopes, compose by far the largest number of the whole sub-order, and 

 will be first described. 



HORNED RUMINANTS. 



The Horned Ruminants with which, anomalous as it may at first seem, have to be included 

 one or two hornless species, on account of their so closely resembling them in other respects 

 have their cranial appendages developed after one or other of two principles. In one group, which, 

 from the fact that the Oxen are included with them, are named the Bovidce, the horns are hollow, 

 straight, or variously-twisted cones, supported upon bony prolongations from the forehead, resembling 

 them in shape upon a smaller scale. These horns are permanent, except in the American Antelope, 

 increasing in size each year, at the same time that they often exhibit transverse markings, which 

 indicate the annual increase. In the other group the Cervidce, or Deer Tribe the horns or antlers 

 are deciduoiis, being cast off each year, to be shortly replaced by others, which share the fate of their 

 predecessors. These antlers are entirely made of bone, and when fully grown are not covered with 

 any less dense investment. 



To commence, then, with the fiovidce, or Oxen, and their allies. 



