COMMON INTEGUMENT 



775 



The cavum tympani is small; it communicates ventrally with the air-cells of 

 the bulla ossea. The tympanic membrane is nearly circular and is not so oblique 

 as in the horse. The auditory ossicles are smaller than those of the horse; the 

 malleus is more curved, the body of the incus is longer, and there is a small promi- 

 nence on the front of the head of the stapes for the attachment of the stapedius 

 muscle. 



The Eustachian tube is small and is only about two inches long. The pharyn- 

 geal opening is small and is situated on the side of the fornix of the pharynx close 

 to the base of the cranium. There is no flap-like expansion, of the cartilage, but 

 the inner liorder of the orifice is formed by a fold of mucous membrane. 



The internal ear has essentially the same arrangement as in the horse. 



COMMON INTEGUMENT 



The thickness of the skin of the ox is greater than that of any of the other 

 domesticated animals; in general it is about 3 to 4 mm., but at the root of the tail 

 and the point of the hock it is about 5 mm. and on the 

 brisket 6 to 7 mm. The variably developed prominence 

 at the anterior part of the pectoral region known as the 

 brisket consists of a fold of skin (Plica colli ventralis 

 longitudinalis), which contains posteriorly a mass com- 

 posed of coarse fibrous trabecular and fat. 



The cutaneous glands are fewer and less developed 

 than in the horse. Except about the natural openings, at 

 the point of the hock, and the flexion surface of the fet- 

 lock, the sweat glands do not form a coil, but are enlarged 

 at the deep end and are variably flexuous. The sebaceous 

 glands are best developed about the natural openings and 

 on the udder, but there are none on the teats. The 

 naso-labial glands form a thick layer under the bare skin 

 of the muzzle. They are compound tubular glands and 

 are lined with cubical epithelium. The openings of their 

 excretory ducts are easily seen. 



The hairs are extremely variable in color and size in 

 the different breeds and in different individuals. The hair 

 of the frontal region is often curly, especially in the bull. 

 There is no mane, and the long hairs of the tail occur only 

 at the end, where they form the "brush" (Cirrus caudse). 



The claws, four in number on each limb, cover the ends of the digits. Those 

 of the chief digits conform in a general way to the shape of the third phalanges, 

 and each may be regarded as having three surfaces. The abaxial or outer surface 

 is convex from side to side, and is marked by ridges parallel with the coronary 

 border. Its anterior part is concave from edge to edge, and the angle which it 

 forms with the ground is about 30°. The interdigital or inner surface is con- 

 cave and grooved ; it touches the opposite claw only at its ends. The inferior or 

 ground surface consists of two parts, viz., a slightly concave sole, which is pointed 

 in front and widens behind, and a prominent bulb of soft thin horn, which is con- 

 tinuous above with the skin. The claw may be regarded as consisting of three 

 parts — periople, wall, and sole. The periople surrounds the coronary border in 

 the form of a flat band, which is about half an inch wide, except at the heels, where 

 it widens to cover the entire surface. The wall forms most of the abaxial or outer 

 part of the claw and is reflected in front upon the interdigital surface. It thins out 

 toward the bulb or heel, which appears, as stated above, to consist of the thin 

 expansion of the periople. The sole occupies the angle of inflection of the wall; 



Fig. 



585. — Claws of Ox, 

 Volar Aspect. (After 

 Ellenberger-Baum, 

 Anat. fiir Kiinstler.) 



