DIGESTIVE SYSTEM OF THE SHEEP 471 
narrow depressions in the form of a V and separated by the central papilla incisiva, 
at the deep anterior ends of which the incisive or naso-palatine ducts open. The 
ridges of the palate, some fourteen in number, are irregular and their edges are 
smooth; most of them alternate with those of the 
opposite side, from which they are separated by the 
median raphé palati. The posterior third or rather 
more is not ridged and presents numerous orifices of 
ducts of the palatine glands. The mucous membrane 
is often more or less pigmented. The soft palate 
resembles that of the ox. 
The mucous membrane of the cheeks is covered 
with large papille, many of which are long and sharp- 
pointed, while others are short and blunt. There is 
also a series of conical papille on the floor of the 
mouth, under the lateral part of the tongue. 
The tongue resembles that of the cx in form, but 
the tip is comparatively smooth; the papillz here are 
very numerous, but short and blunt. This difference 
is in conformity with the dissimilarity in the mode of 
prehension of the two species. The prominence of 
the dorsum is commonly not so pronounced nor so 
sharply marked off in front as in the ox. The root 
is smooth. The mucous membrane of the dorsum is 
often pigmented in spots. 
The dental formula is the same as that of the 
ox. The incisor teeth form a narrow and strongly 
eurved arch. The crowns are long and narrow; their 
labial surfaces are strongly convex and end at a sharp 
edge which is used in cropping the grass. The roots 
are more firmly embedded than in the ox. The cheek 
teeth resemble those of the ox, but have a thinner i, Dental’ pads |S. papilla in 
layer of cement, which is often blackened by deposits  cisiva; 3, 3, openings of incisive 
from the food. The average periods of eruption of ‘°#D%s: 4 Tphé palati; 5, phil- 
trum; 6, conical papill® of cheek; 
Fic. 404.—P arate oF SHEEP. 
the teeth are indicated in the subjoined table: 7, tonsils; |S) palatine arch. 
TEETH TEMPORARY PERMANENT 
Una ee eae At birth or first week... .....1 to 114 years 
Ib Seaeee First or second week... - . ..-114 to 2 years 
ly eee Second or third week......... 214 to 3 years 
leis Seer Third or fourth week......... 3 to 4 years 
Py 
P Sore 2\to Giweeks. 22. ..+...-...--14% to 2 years 
P; 
Wile 2 0 cif Saye ae Sete eee ee 3 months (lower), 5 months (upper) 
2b. < ou Rd aoe GRC SE SRE eaaae ay ae 9 to 12 months 
TUN 9 of 32a SS eee 114 to 2 years 
The salivary glands resemble those of the ox in general. The parotid gland 
is darker in color and more compact in texture than the mandibular. It is rounded 
in outline, but has a pointed cervical angle at which the external jugular vein 
emerges. The duct leaves the lower part of the anterior border of the gland and 
runs forward over the masseter muscle, about an inch and a half (ea. 3.4 em.) 
above the ventral border of the ramus; it opens opposite the third or fourth 
cheek tooth. 
The tonsil is bean-shaped and about half an inch (ca. 12 mm.) in length. It 
1 A lateral view of the teeth is given in the description of the skull. 
