OLFACTORY AND GUSTATORY ORGANS 



781 



The claws (Ungues) correspond in form to the ungual part of the distal pha- 

 langes which they inclose. The horn of the claw consists of a body or wall and a 

 sole. The former is strongly curved in both directions, and is compressed laterally. 

 Its root or coronary border fits into the depression under the bony collar or ungual 

 crest of the third phalanx and is covered by skin. The lateral borders converge 

 and inclose the sole anteriorly. The matrix presents a coronary part which bears 

 papilla? only near the coronary border. On the dorsal surface it is thickened 

 to form a ridge, and the corresponding part of the horny covering is thick and 

 maintains the pointed character of the claw. The matrix of the sides of the wall 

 bears small laminae which converge to the matrix of the sole. The latter is papil- 

 lated. When the flexor muscles are inactive, the distal phalanges and the claws are 



r3 



Fic. 5S7. — Pads of Paw of Dog. 



a, Carpal pad; h, metacarpal pad; c^-c^, digital pads. 



(From Leisering's Atlas.) 



Fig. 588. — Half of Claw of Dog, Inner Surface. 



a, a'. Coronary part, 6, volar part of wall; 



c, sole; d, section of c; e, section of wall; 1, coronary 



border; 3, apex; 3, dorsal surface. (From Leisering's 



Atlas.) 



maintained in dorsal flexion by two elastic ligaments. These arise from the 

 tubercles at the proximal end of the second phalanx and converge to the dorsal 

 aspect of the ungual crest of the third phalanx. 



OLFACTORY AND GUSTATORY ORGANS 



The olfactory region lies above the lamina transversa, which separates it from 

 the naso-pharyngeal meatus. The mucous membrane is distinguished by its 

 thickness and yellow color, and is very extensive. It covers about half of the large 

 ethmoturbinals, and one-third to one-half of the septum nasi. The ethmoturbinal 

 which projects into the frontal sinus and the adjacent inner wall of the sinus is 

 olfactory in character. Olfactory nerve-fibers ramify in the vomero-nasal organ 

 (of Jacobson). 



The gustatory apparatus presents no special features of importance. 



