16 



closing the opening of the Tuba Eustachiana or Eustachian Trumpet, or passage leading to the 

 ear : for a particular description of this part see Plate II. of the Section of the Hcad above 

 referred to. 19 The Velum Palati, without an Uvula in the horse. 20 The great cavity of 

 the Fauces, leading into 21 the passage of the ^fsopÄag^ui or Gullet, lined throughout with 

 a thick white membrane or cuticle, loosely adhering to the canal, and in the ruminants wholly 

 coverine the maw, or first stomach, and in the horse extending over a considerable portion of 

 the Upper part of the stomach. 



Of the Air Passages. — These parts have been attempted to be introduced entire by Mr. 

 Kirtland, having been represented in section in the Plate of the head above referred to. 24 Is 

 the Thyroid Cartilage, being part of the Larynx, or head of the windpipe. 25 TheEpiglottis, 

 or Valve, which shuts down during deglutition, preventing the food from passing into tlie pipe 

 or trachea. 26 The short limb of the Os Myoides. 27. The convex edge of the Aretenoid 

 Cartilage. 28 The same covered with muscle. 29 The Cricoid Cartilage. 30 The beginning 

 ofthe Trachea, or Wind-Pipe : this part is very frequently crushed, and more or lessinjured, 

 by rough hands squeezing and pinching it under pretence of ascertaining broken wind, of whieh 

 it appears to be an uncertain criterion; or at least but in the last stage of it, when other Symp- 

 toms and an attention to the nostrils and flanks are more sure guides. Two fine horses I have 

 Seen destroyed by this gross practica, and others with difficulty of breathing, which has never 

 been recovered from, the membraue lining the pipe being dislodged by the gripe and stopping 

 the passage has created suffocation. See article Broken Wind in Rees's Cyclopaedia. 31 

 Tlie Cartilaginous Rings ofilie Trachea, about sixty in number, at the lower part of the pipe 

 where it enters the ehest they are converted into oblong thin elastic plates,at least at the back 

 part of the trachea, and tiled one over another, for permitting perhaps the contraction or 

 coUapse ofthe canal to the quantity of air required by the liuigs. 



Of the Spine, or Back Bone. — The irregulär line described by the spine is truly remark- 

 able and worthy attention, and is exposed advantageously by this sectional view : it appears 

 inclining downwards in both directions from its two extremities to form a curve at its lowest 

 part over the fore limbs, and determining as it were the weight upon these upright pillars of 

 Support ; the processes of the withers of prodigious length filling up and strengthening this 

 cxternal hoUow part ; the ends or extreme points of these bones serve also to form the 

 prominent outlineof the witheis, a part in its contour nobly characteristic of this raceofaniraals: 

 the extraordinary length of these bones also most usefully serve for the application of the elastic 

 ligamentssupportingthe neck and head, which islarger perhaps thaninalmost any other animal, 

 and farther advanced before the body, and they aft'ord a space for the lodgment ofthe muscles 

 tosustain and move these parts. Along the back and loins the spineis gently raised into an arch 

 upwards, useful in opposing the weight of the suspended viscera in the cavity of the abdo- 

 men, and in bearing burthens externally brought upon the back; ascending rapidly to the head 

 from the fore legs, in its passage it is carried almost to the front parts of the neck, w here, from 

 an external view of the animal the eye would bardly be led to suspect it : in the Camel the 

 hoUow neck makes this construction rauch more externally obvioiis. A second and lesser arch it 

 formed at the sacrum, being somewhat raised above and convex also below, affording superior 



width 



