THE EAR THE SKIN AND APPENDAGES 901 



The deep part of the cartilage of the third ej-elid is broad and spoon-hke, the 

 superficial part somewhat anchor-shaped. In addition to the gland which sur- 

 rounds the deep part of the cartilage, there is a deeper one, often termed the gland 

 of Harder (Glandula palpebrte tertise profunda), which is surrounded by a distinct 

 capsule and a blood-sinus. This gland is brownish or yellowish-gray in color, 

 elliptical in outline, and about an inch (2-3 cm.) in length. It is situated deeply 

 below the attachment of the ventral oblique muscle. 



The caruncula lacrimalis has the form of a ridge; it divides into two branches 

 which join the skin at the medial commissure. It is red in color and contains 

 numerous large coil glands. 



The lacrimal gland is mucous in type. There is no lacrimal sac, and the two 

 lacrimal ducts pass through separate openings at the infraorbital margin. The 

 naso-lacrimal duct is usually short and opens into the ventral nasal meatus at the 

 posterior end of the ventral turbinate.^' The eyeball appears small, partly on 

 account of the narrowness of the palpebral opening; it closely approaches the spheri- 

 cal form. The cornea, although in reality almost circular, appears oval when viewed 

 from the front, the medial end being much the broader. The chorioid has no 

 tapetum. The iris is usually dark grayish-brown or yellowish-brown, but sometimes 

 has a blue tinge. The pupil is a transverse oval in ordinary light, but almost 

 circular when dilated; granula are not present. The optic papilla is nearer the 

 posterior pole than in the horse and ox, and has a distinct central artery and vein. 



THE EAR 



The external ear differs considerably in size, thickness, and position. It may 

 be carried vertically, inclined inward, or hang downward. It is relatively wide and 

 is little curved except at the base. The concave surface presents several cutaneous 

 ridges which correspond approximately with the long axis of the ear. The anterior 

 border of the concha is strongly recurved in its lower part, and divides into two 

 branches, one of which passes almost horizontally backward in the cavum conchse, 

 while the other continues the general direction of the border. The posterior border 

 is slightly concave above, strongly convex below, forming a prominence somewhat 

 analogous to the lobule of the human ear. The osseous external acoustic meatus 

 is very long and is directed ventrO-medially. The tympanic membrane is almost 

 circular. The tympanic cavity proper is small, but it is continuous with the numer- 

 ous cells of the large bulla ossea. The auditive or Eustachian tube is short; its 

 pharyngeal opening is situated in the upper part of the wall of the pharynx, imme- 

 diately behind the posterior nares. It is somewhat infundibular, and is bounded 

 medially by a thick fold of mucous membrane (Torus tubarius) . 



THE SKIN AND APPENDAGES 



The thickness of the skin in improved breeds is 1 to 2 mm. Fat usually accu- 

 mulates in the subcutis and forms a distinct and often extremely thick panniculus 

 adiposus over the greater part of the body. The sebaceous glands are in general 

 small and much fewer than in the other animals. The sweat glands, on the other 

 hand, are large, yellow or brownish in color, and are in many places visible to the 

 naked eye. At the medial side of the carpus there are small cutaneous diverticula, 

 the so-called carpal glands, into which numerous compound coil glands open. Large 

 glands also occur in the skin of the digits and interdigital space. Compound 

 tubular glands are present in the skin of the snout. Large sebaceous and sweat 



1 The lower punctum lacrimale is frequently absent and the corresponding duct therefore 

 blind. There is often a duct or its remnant which opens below the ventral turbinate fold, but is 

 not connected behind with the functional duct. 



