Part 129

The tongue of the ox is often variably pigmented. The root and body are wider than that of the horse, but the free part is more pointed. The posterior part of the dorsum forms a remarkable elliptical prominence, which is sharply defined in front. The filiform papillæ in front of this prominence are large and horny, with sharp points directed backward. They impart to the tongue its rasp-like roughness. The papillæ on the prominence are large, broad and horny; some have a blunt conical form, others are rounded or flattened. Behind the prominence, the papillæ are long and soft, i. e., not horny. The fungiform papillæ are numerous and distinct; they are scattered more generally over the dorsum and edges of the free part. The vallate papillæ are about twenty or thirty in number; they are smaller than those of the horse, and are irregularly distributed on either side of the posterior part of the prominence of the dorsum. The foliate papillæ and the lingual fibrous cord are absent. The muscles are well developed; the hyo-glossus arises by additional portions from the great and middle cornua of the hyoid bone. The tongue is highly protractile and is the chief organ of prehension.

THE TEETH

The dental formula of the ox is:

( 0 0 3 3 ) 2 ( I - C - P - M - ) = 32 ( 4 0 3 3 )

The =incisors= are absent from the upper jaw. There are eight incisors in the lower jaw, arranged in a somewhat fan-like manner. They are simple teeth, without infundibulum. The crown is white, short, and shovel-shaped. The root is rounded, and is embedded in the jaw in such a manner as to allow a considerable degree of movement. There is a distinct =neck=. In addition to the simple numerical designation, the following terms are commonly applied to the individual teeth: pinchers or central, first intermediate, second intermediate, and corner incisors. It is probable that the latter are much modified canines. The incisors of the ox do not advance out of the alveoli, as is the case in the horse; in old age, however, the gum retracts so that the roots are partly exposed and may come into wear.

FIG. 284.—INCISOR TEETH OF OX, LINGUAL ASPECT.

C.s., Caruncula sublingualis. ]

FIG. 285.—INCISOR TOOTH OF OX.

24′, Lingual surface of crown; 24″, masticatory surface. The crown is clearly marked off from the rounded root by a neck. (After Ellenberger-Baum, Anat. für Künstler.) ]

The =deciduous incisors= differ from the permanent set chiefly in being much smaller. The crowns are narrower and diverge more.

The =canines= are absent (unless the fourth incisors be considered to represent them).

FIG. 286.—SKULL OF OX TWO YEARS OF AGE, SCULPTURED TO SHOW THE EMBEDDED PARTS OF THE TEETH.

11–4, Permanent incisor teeth, the third and fourth not erupted; Di.3, 4, third and fourth deciduous incisors; P1–3, upper permanent premolars, only first erupted; Dp.2, 3, deciduous premolars; M1–3, molars. ]

The =cheek teeth= (Fig. 286) resemble those of the horse in number and general arrangement. They are, however, smaller, and also differ in the fact that they progressively increase in size from before backward. This feature is so marked that the first tooth is quite small, and the space occupied by the first three (i. e., the premolars) is only about one-half of that required for the posterior three (i. e., the true molars). The enamel folds stand out even more prominently in relief on the masticatory surface than in the horse. The occurrence of wolf-teeth is rare.

The formula of the deciduous teeth is:

( 0 0 3 ) 2 ( Di — Dc — Dp — ) = 20 ( 4 0 3 )

TABLE OF AVERAGE PERIODS OF ERUPTION OF THE TEETH IN THE OX │ TEETH │ ERUPTION │ A. Temporary: │ First incisor (Di 1) │Birth to 3 weeks. Second incisor (Di 2) │ „ Third incisor (Di 3) │ „ Fourth incisor (Di 4) │ „ ──────────────────────────────┼────────────────── First cheek tooth (Dp 1) │Birth to 3 weeks. ──────────────────────────────┼────────────────── Second cheek tooth (Dp 2)│Birth to few days. Third cheek tooth (Dp 3) │ „ ──────────────────────────────┼────────────────── │ B. Permanent: │ First incisor (I1) │1½ to 2 years. Second incisor (I2) │2 to 2½ years. Third incisor (I3) │3 years. Fourth incisor (I4) │3½ to 4 years. First cheek tooth (P1) │2 to 2½ years. Second cheek tooth (P2) │1½ to 2½ years. Third cheek tooth (P3) │2½ to 3 years. Fourth cheek tooth (M1) │5 to 6 months. Fifth cheek tooth (M2) │1 to 1½ years. Sixth cheek tooth (M3). │2 to 2½ years.

The eruption of the permanent teeth is subject to great variation. The above figures are the average of observations of improved breeds under favorable conditions.

THE SALIVARY GLANDS

The =parotid gland= is smaller than that of the horse, and is light red-brown in color. It has somewhat the form of a very narrow long triangle, and lies chiefly on the posterior part of the masseter muscle. The thick wide upper end partly covers a large subparotid lymph gland. The small lower end is bent forward and fits into the angle of union of the jugular and external maxillary veins; it lies on the submaxillary gland. The parotid duct leaves the lower part of the deep face; in its course it resembles that of the horse, but it pierces the cheek opposite the fifth upper cheek tooth.

The =submaxillary gland= is very large, and is pale yellow in color. It is covered to a small extent by the parotid. Its general form resembles that of the horse, but its lower (or anterior) end is large and rounded, and is separated by a small interval only from the gland of the other side. This part can be distinctly felt in the living animal, and is related externally to a large submaxillary lymph gland. The duct leaves the middle of the superficial face of the gland, crosses the stylo-hyoideus and the intermediate tendon of the digastricus, and is then disposed as in the horse.

The =sublingual gland= consists of two parts. The dorsal part (Glandula sublingualis parvicanalaris) is long, thin, and pale yellow in color. It extends from the anterior pillar of the soft palate about to the symphysis of the jaw. It has numerous small tortuous ducts (Ductus sublinguales minores), which open between the papillæ under the side of the tongue. The ventral part is shorter and thicker, and is salmon pink in color. It has a single duct (Ductus sublingualis major), which either opens alongside of or joins the submaxillary duct.

THE PHARYNX

The pharynx is short and wide. The vault (Fornix pharyngis) is divided into two cul-de-sacs by a median fold of mucous membrane (Septum nasi membranaceum), which is a continuation of that of the septum nasi; on the outer wall of each is the relatively small opening of the Eustachian tube, which is covered by a simple fold of mucous membrane. The posterior nares are small. The entrance to the œsophagus is large.

FIG. 287.—SALIVARY GLANDS OF OX.

a, Parotid gland; b, submaxillary gland; c, inferior, d, middle, and e, superior buccal glands; f, labial glands; g, buccinator nerve; h, buccinator vein; 1, masseter (cut); 2, ramus of mandible; 3, zygomaticus muscle; 4, conical papillæ of lip; 5, buccinator muscle. (After Ellenberger, in Leisering’s Atlas.) ]

On the dorsal wall of the pharynx are two large pharyngeal lymph glands, which, when enlarged, cause difficulty in swallowing and breathing (Fig. 281).

THE ŒSOPHAGUS