290 THE HORSE. 



The latter is a very complicated and delicate orgai ; but its forma- 

 tion does not differ in any essential features from that of the other 

 vertebrate animals, nor are the diseases attacking it in the horse 

 of any particular importance, so that its description will be omitted. 



THE ORGAN OF TOUCH. 



The sense of touch is necessary for the proper appreciation 

 of the mechanical form and nature of the objects placed in appo- 

 sition to the body, and of their temperature. It is seated gener- 

 ally in the terminations of the nerves of sensation on the skin ; but 

 there are certain parts specially endowed with these nerves, which 

 in the horse are the lips and the four extremities. 



Every part of the skin is sensible to impressions from ex- 

 ternal objects, but the sense of touch, such as we possess in the 

 fingers, can only be said to reside in the lips, and partially in the 

 feet. All these parts are profusely supplied with nerves of sensa- 

 tion, and the horse may often be observed to use them in ex- 

 amining external objects, especially his lips, which are the most 

 delicate of his organs of touch. Mr. Rarey has lately drawn special 

 attention to this subject; but it has long been known to those 

 who are familiar with the habits of the horse. The feet are also 

 largely supplied with nerves, though not to the same extent as the 

 human fingers, and being covered with horny matter, the sensi- 

 bility of the surface is greatly reduced ; still there can be no doubt 

 that the horse uses them occasionally in making out the nature of 

 objects presented to him, and this is especially the case with the 

 fore feet, though it will sometimes happen that the hind extremi- 

 ties are used for the same purpose, as for instance, in ascertaining 

 the nature of a hard body before kicking at it. 



THE FOOT. 



It is necessary to examine the structure of the foot most 

 carefully, not as an object of curiosity connected with the sense of 

 touch, but on account of the numberless diseases and accidents to 

 which it is subject. No part of the horse is so liable to the effects 

 of hard work and mismanagement as this, and there is conse- 

 quently none which more requires our care both in health and 

 disease. 



The parts, entering into the composition of the foot, will be 

 better understood by a reference to the annexed section of the 

 phalanges or fingers terminating the metacarpal or metatarsal 

 bones, as the case may be, with their investments. It will be seen 

 that there is very little space between the pedal bone and the 

 crust, which, together with the sole, forms a horny case or 

 natural shoe, for the sensible and delicate investmer. ts of the 

 bone. So small is this space, that when inflammation takes place 



