68 ' AMEBICAN FARMER'S HORSE BOOK. 



at different times, in all animals, but in the horse more, per- 

 haps, than in any other. As fast as it is collected in the 

 kidneys, the urine passes down to the bladder through the 

 long excretory ducts, called the ureters, of which there is one 

 for each kidney. 



The bladder is the oval membranous bag, which serves 

 as a reservoir for the urine. Here it accumulates unjil its 

 quantity begins to occasion inconvenience, when the animal, 

 by a voluntary effort,i expels it. Thus the great annoyance 

 of a constant dribbling is prevented. The bladder has three 

 coatings. The outer one is an extension of the peritoneum, 

 but covering only a part of the bladder. Kext to this, and 

 upon the outside of the bladder for a great part of the lat- 

 ter's surface, is the muscular coating, composed of two sets 

 of muscles, crossing each other transversely, as in the intes- 

 tines. The internal coating is the mucous membrane, which 

 lines all the hollow viscera. The urethra has its origin at 

 the neck of the bladder. It is the canal which carries off 

 the urine. Its orifice can be entirely closed, at the horse's 

 pleasure, by the contraction of the powerful muscle which 

 surrounds the neck of the bladder. 



The urinary organs have a number of diseases. These 

 will be fully described in the proper place. 



This completes all that our limits will permit us to pre- 

 sent of the anatomy of the horse — all, indeed, that the purpose 

 of our work requires. The reader who wishes to pursue this 

 subject further, is referred to those highly scientific and valu- 

 able works, Percival's " Anatomy of the Horse," and " The 

 Horse in the Stable and the Field," by J. H. Walsh, (Stone- 

 henge.) 



