614 THE DISEASES AND DISORDERS OF THE OX. 



Serena, then, is a malady of the nervous mechanism of vision, 

 and it may result from injury or disease of the brain, or as a 

 consequence of some derangement of the nervous system. 



In conclusion, it is to be borne in mind that the disorder is 

 probably capable of being hereditarily transmitted, and therefore 

 that no animal which is suffering from true amaurosis ought to 

 be used as sire or dam. The only remaining point in regard 

 to the eye of the sheep is that, being greatly exposed, it is very 

 liable to suffer from injuries or otherwise. In two or three cases 

 the eye has been removed owing to its being enlarged in 

 consequence of some new formation, and when dropsical it has 

 been punctured. 



TUMOURS, RINGWORM, AND CONCLUSION. 



Tumours, sometimes of such large size as to push the eyeball 

 out of its situation, may occasionally be seen. They have been 

 removed, and after the removal have occasionally recurred. 

 The best course is not infrequently to be found in fattening the 

 animal for the butcher. 



Ringworm in the region of the eyes and ears is very common. 

 For particulars of this complaint the reader is referred to 

 previous pages. 



How infinitely important is the well-being of these two organs, 

 the eye and the ear, to the happiness and prosperity of human 

 beings, can perhaps be fully realised only by those who are so 

 unfortunate as to be deprived of the use of one or other or both 

 of these means of communication betwixt living animals on the 

 one hand and the wonderful earth on the other in which they 

 sojourn for a season, being then resolved into the lifeless 

 elements which represent the end of all kinds of living things, 

 so far as this world is concerned. 



The eye and the ear are alike the most important and the most 

 wonderful of the mechanisms whereby impressions of surrounding 

 objects are conveyed to the brains of living animals. If we 

 possessed useless auditory organs or defective ones, we should 

 be unconscious, or but imperfectly conscious, of the many 

 pleasing, weird, and thrilling sounds, which abound throughout 

 nature ; we should be unable, or only inadequately able, to hear 

 and converse with our fellow-men; we should be shut out from one 

 of the greatest enjoyments, the hearing of sweet tones of silvery 



