THE RABBIT 437 



magnum or capitatum, and the fourth, which represents 

 two fused, as the unciform or os hamatum. On the hinder 

 side of the wrist is a small pisiform bone. There are five 

 digits, of which the first is the shortest and the third the 

 longest. In the hind-limb, the femur has a prominent 

 head, below which are three rough prominences, the greater 

 trochanter on the outside, the lesser trochanter on the inner 

 side, and the third trochanter below the great trochanter. 

 At the lower end of the bone are two large condyles for the 

 tibia. A knee-cap or patella covers the knee joint and is 

 connected by ligament with the tibia. The tibia and fibula 

 are fused at their lower ends only. The latter is a small 

 splint of bone outside the former, which is straight and 

 stout and bears in front a prominent cnemial crest. In the 

 ankle the bones, like those of the wrist, are arranged in two 

 rows with a central bone between them. The first row 

 contains, as in the frog, two bones, the astragalus or talus, 

 which corresponds to a fused tibiale and intermedium, and 

 the fibulare or calcaneus, which lies outside the astragalus 

 and projects backwards to form the heel. The central 

 bone is known as the navicular.. The distal row consists 

 of three bones, that which corresponds to the missing first 

 digit being absent, and those which correspond to the 

 outer two digits being fused together. The innermost of 

 the remaining bones of the row is known as the meso- 

 cuneiform, the next as the ectocuneiform, and the third as 

 the cuboid. The metatarsals are long and there are four 

 digits. 



The mouth differs from that of the frog in the possession 



of a palate — an inner roof which separates 

 Alimentary from the mouth a narial passage. By this 

 Mouth" Teeth passage the approach from the nostrils to the 

 and Pharynx, mouth is prolonged backwards, so that the 



internal nares open into the pharynx instead 

 of into the forepart of the mouth (Fig. 321). The first part 

 of the inner roof is strengthened by the horizontal pro- 

 cesses of the premaxillary, maxillary, and palatine bones 

 (p. 431) and is known as the hard palate; the hinder part 

 is purely fleshy and is known as the soft palate. The narial 

 passage lies above the palate and below the true olfactory 

 chambers. Over the hard palate it is not separated from 



