Anatomy and Physiology of the Larynx. 73 



^ We will, therefore, notice briefly the structure and func- 

 tions of the horse's larynx, before venturing on the attempt 

 to elucidate the nature and causes of the changes which 

 have been considered so mysterious, that nothing but base- 

 less conjectures could be offered to account for them. 



Anatomy of the Larynx. 



The horse's larynx is situated between the branches of 

 the lower jaw, beneath the lower end of the parotid gland, 



[^ -Fig. 1. — UPPEE PART AND APERTURE OF THE HORSE's LARYNX. 



a a, Arytenoid Cartilages ; 6 6, Vocal cords, forming the pars 

 iiocales ; e, Vocal or Morgagni's Ventricle ; d, Epiglottis ; e, Thyroid 

 Cartilage and Thyro-Epiglottidean Ligament ; /, Arv-Epiglottidean 

 fold ; g, Glottis ; h, Inferior border of the Arytsenoid Cartilage which, 

 with its fellow on the opposite side, forms the pars respiratoria ; 

 i i, Processi musculares of the Arytenoid Cartilages ; jj, Dilator 

 muscles of the larynx. 



which partially covers it on each side. It is the commence- 

 ment of the windpipe, its upper opening being directed 

 towards the spacious cavity at the back of the mouth called 



