31 AN. 



329 



The foot is completed by five metatarsals, and fourteen 

 phalanges, of which two belong to the great toe and three to each 

 of the other digits. In the rabbit the great toe (hallux) is only 

 represented by a process of the 2nd metatarsal, there being no 

 distinct equivalents of the internal cuneiform (tarsale 1) and 

 1st metatarsal with the two corresponding phalanges, of the 

 human foot. 



3. Digestive Organs. The only parts of the alimentary canal 

 which call for special notice are mouth-cavity, pharynx, and caecum. 



Mouth and Mouth-cavity. The pathological condition known 

 as hare-lip must not be confounded with the cleft upper lip of 

 rabbit and hare. The upper 

 boundary of the mouth is formed 

 to begin with by a median fronto- 

 nasal process and a maxillary pro- 

 cess growing forward on each side 

 (<:f. Fig. 94) from the mandibular 

 arch. This is the permanent 

 condition in a dogfish (Fig. 46), 

 but in chick, rabbit, and man, 

 the fronto-nasal and maxillary 

 processes fuse together and con- 

 stitute a continuous ridge within 

 which premaxillae and maxillae 

 develop. Failure of this union Fig. 102. iM AN. Junction of Small 

 on one side is the cause of single and Large Intestines (from Mac- 

 hare-lip, while failure on both 

 sides results in double hare-lip. 

 The cleft in a rabbit's lip is median, and does not affect the hard 

 parts. 



There are no papilla? foliatae on the tongue, the circumvallate 

 papillae are from 7 to 1 2 in number, and arranged on the pos- 

 terior part of the back of the tongue in the form of a V with 

 backwardly directed apex. 



The upper and lower teeth are arranged in two horseshoe- 

 shaped curves. There are no gaps, and the canines are not dis- 

 proportionately large. The dental formula is 



allster. 1, Colon; 2, caecum ; 3, 

 vermiform appendix ; 4, ileum. 



2 2 



1-1 



2-2 



