THE ANATOMY OP THE OX. 41 



these cells extend through the whole of the bone. Moreover, we 

 find that the vacuities in the horn-cores are continuous with the 

 largely-developed frontal sinuses, and these, in their turn, are 

 likewise prolonged into the parietal bones, and even into the 

 occipital bone. In fact, the cavities extend from the extremities 

 of the cores to the orbit, and nearly as far backwards and down- 

 wards as the foramen magnum. The two nostrils are, as it were, 

 merged into one. Indeed, there is one continuous cavity from 

 the muzzle to the tip of the horn and from one muzzle to 

 the other. 



Inflammation of the Frontal Sinuses. — The sinuses are 

 lined internally by a prolongation of the membrane of the nose, 

 and when one part of it is inflamed, the whole is liable to be 

 affected. Consequently, nasal gleet in the ox ought to be 

 examined and properly treated at once. After a little cough, 

 with slight nasal discharge, a beast may rapidly become dull and 

 drooping, and carry the head on one side. Grubs or worms may 

 have crept up the nostril and be lodged within some of the sinuses, 

 or perhaps inflammation of the membrane of the nose, the result 

 of an ordinary cold, may extend along the cavity, and be more 

 intense in some particular spot than in others. Even suppura- 

 tion may supervene, and it is more common near the root of one 

 of the horns. The veterinary surgeon either opens the skull at 

 the root of the horn with a trephine, or cuts off the horn at its 

 root. More than a pint of pus may escape from the orifice. 

 The opening into the sinus should, however, be speedily closed. 

 Occasionally the ox suff'ers greatly from the larva of a species of 

 fly, which creeps up the nose and lodges in some part of the 

 sinus. The ox is tortured much more than the sheep from 

 this cause, and the symptoms may even resemble those of in- 

 flammation of the brain. 



The supra-orbital foramina are double, situated far backwards, 

 and continued by a groove. The frontal arch articulates with 

 the zygoma. The processes which form the orbital arches rest 

 by their summits on the zygomatic bone. The supra-orbital 

 foramen is a true and frequently multiple canal. The inferior 

 border of the frontal bone is deeply notched in its middle to 

 receive the nasal bones. In the sheep and goat the frontal bone 

 is relatively less extensive and strong than it is in the case of 

 the ox. It does not ascend to the summit of the head, and 



