CHAPTER IX 



THE ORGANS OF SPECIAL SENSE ^ 



The organs of sj)ecial sense have been alluded to in the pre- 

 ceding chapter. It will suffice here to give a short description of 

 the eye, the ear, and the organs of taste and smell. 



The Eye. The eye is an organ specially adapted to receive 

 and retain visual impressions. It is a globular structure, con- 

 sisting for the greater part of a tough white fibrous coat, the 



Fig. 51. Vertical section of the eye of the horse, natural size, c, cornea ; 

 I, lens; i, iris; cj), ciliary pi'ocess ; l2>, ligamentum pectinatum ; cbn, 

 position of ciliary muscle; d, suspensory ligament of lens; on, optic 

 nerve, showing its curve. Note its attachment to the lower part of the 

 globe. (From Smith, Messrs Bailliere, Tindall and Cox.) 



sclerotic coat, bounded in front by a transparent watch-glass-like 

 structure caUed the cornea. Inserted into the sclerotic coat to- 

 wards the front portion of the eyeball are six muscles, the superior 

 and inferior oblique muscles, the superior and inferior rectus 

 muscles, and the internal and external rectus muscles. These 

 muscles, which all find their origin in the rear of the bony orbit 

 1 By Capt. E. T. Hainan, M.A. 



