CAMELS AND LLAMAS. 



403 



THE LEFT 

 FOKE-FOOT OF THE 



CAMEL. (From 

 Dawkins.) 



An important point of distinction is that the front of the upper jaw is furnished 

 with incisor teeth ; it is true, indeed, that in the adult state there is only a single 

 pair of these teeth remaining, but in young animals there are, as in pigs, three 

 pairs. Then, again, both jaws are furnished with tusks or canine teeth ; those of 

 the lower jaw being sharply pointed, and separated by an interval 

 from the incisors, instead of resembling the latter and forming 

 with them a continuous series, as we have seen to be the case in 

 the chevrotains and the true Ruminants. The molar teeth have 

 tall and crescent-shaped crowns, which, however, are not precisely 

 similar to those of the group last-named ; and one, or sometimes 

 more, of the premolar teeth generally has a simple pointed crown, 

 like that of a canine, and is not in contact with the other teeth 

 of the cheek-series. These isolated premolar teeth are seen in 

 the figure of the skeleton of the camel, in the gap between the 

 tusks and the other cheek-teeth. 



The limbs are long, and the thigh is placed nearly vertically, 

 so that the true knee is more detached from the small hind- 

 quarters of the body than is usually the case in Ungulate 

 mammals. The lower portion of the legs is composed of a 

 cannon-bone supporting two toes, without any trace of the lateral 

 toes or their metacarpal bones. The cannon-bone differs, how- 

 ever, from that of the true Ruminants, in that the two pulley-like 

 surfaces at the lower end, instead of being placed side by side 

 and furnished with a distinct ridge in the middle of each, are divergent and perfectly 

 smooth. The bones of the first joint of the toes are also longer and more expanded 

 at their lower ends than in the true Ruminants ; the second pair being broad and 

 flattened, while the third form mere nodules, quite unlike the symmetrical ones of 

 the latter group. The feet form broad expanded cushion- 

 like pads (from which the group derives its title of 

 Tylopoda), of which the under surface is undivided, while 

 the front shows a division into two toes, each of which 

 bears a broad nail on the upper surface. The ankle-joint 

 differs from that of the true Ruminants in that the two 

 bones lying immediately below the astragalus, remain 

 distinct, whereas in the former they unite into a compound 

 bone, termed the naviculo-cuboid. A further distinction is 

 to be found in the divided upper lip, like that of a hare ; 

 while the elongated neck is characterised by the great 

 length of its component vertebrae. These vertebrae ex- 

 hibit certain peculiarities of structure into the considera- 

 tion of which we need not enter here ; but it must be 

 observed that they resemble those of the true Ruminants 



in that the process in front of the second vertebra, by which it articulates with 

 the first, is spout-shaped. Here, then, we have another instance of a similar 

 structure being independently acquired in two distinct groups. The head is carried 

 high in the air, with the upper part of the neck nearly vertical ; and is unprovided 



WATER-CELLS IX STOMACH OF 

 CAMEL. 



