250 



This is seen, to a lesser extent, in all painful inflammations of tlie eye, 

 and to a very marked degree in lockjaw, when the spasm of the muscles 

 of the eyeball draws the latter deeply into the orbit and projects for- 

 ward the masses of fat and the cartilage. The brutal practice of cut- 

 ting off this apparatus, whenever it is projected, necessitates this ex- 

 planation which, it is hoped, may save to many a faithful servant a 

 most valuable appendage. That the cartilage and membrane may be- 

 come the seat of disease is undeniable, but so long as its edge is thin 

 and even, and its surface smooth and regular, the mere fact of its pro- 

 jection over a portion or the whole of the eyeball is no evidence of 

 disease in its substance, nor any warrant for its removal. It is usually 

 but the evidence of the presence of some pain in another part of the 

 eye, which the suffering animal endeavors to assuage by the use of this 

 beneficient provision. For the diseases of the cartilage itself see 

 " Encephaloid Cancer." 



LACHRYMAL APPARATUS. 



This consists, first, of a gland for the secretion of the tears, and, sec- 

 ond, of a series of canals for the conveyance of the superfluous tears 

 into the cavity of the nose. 



The gland is situated above the outer part of the eyeball, and the 

 tears which have flowed over the eye and reached the inner angle are 

 there directed by a small conical papilla (lachrymal caruncle) into two 

 minute orifices, and thence by two ducts (lachrymal) to a small pouch 

 (lachrymal sac) from which a canal leads through the bones of the face 

 into the nose. This opens in the lower part of the nose on the floor of 

 the passage, and a little outside the line of union of the skin which lines 

 the false nostril with the mucous membrane of the nose. In the ass 

 and mule this opening is situated on the roof instead of the floor of the 

 nose, but still close to the external opening, 



EXAMINATION OP THE EYE. 



To avoid unnecessary repetition the following general directions are 

 given for the examination of the eye : The eye, and to a certain extent 

 the mucous membrane lining the eyelids, may be exposed to view by 

 gently parting the eyelids with the thumb and forefinger pressed on 

 the middle of the respective lids. The pressure, it is true, causes the 

 protrusion of the haw over a portion of the lower and inner part of the 

 eye, but by gentleness and careful graduation of the pressure this may 

 be kept within bounds, and oftentimes even the interior of the eye can 

 be seen. As a rule it is best to use the right hand for the left eye, and 

 the left hand for the right, the finger in each case being pressed on the 

 upper lid while the thumb depresses the lower one. In cases in which 

 it is desirable to examine the inner side of the eyelid farther than is 

 possible by the above means, the upper lid may be drawn down by the 

 eyelashes with the one hand and then everted over the tip of the fore- 



