14 INTRODUCTION 



body is inclosed within a hide, a skin covered with 

 hair ; and if this hide be taken off, we find a great mass 

 of flesh or muscle, the substance which, by its power of 

 contraction, enables the animal to move. On removing 

 this, we have a series of bones, bound together with 

 ligaments, and forming the skeleton. Pursuing our 

 researches, we find within this framework two main cavi- 

 ties : one, beginning in the skull and running through 

 the spine, containing the brain and spinal marrow ; the 

 other, commencing with the mouth, contains the gullet, 

 stomach, intestines, and the rest of the apparatus for 

 digestion, and also the heart and lungs. Examinations 

 of this character would give us the Anatomy of the 

 horse, or, more precisely, Hippotomy. The study of the 

 bones alone would be its Osteology ; the knowledge of 

 the nerves would belong to Neurology. If we examined, 

 under the microscope, the minute structure of the hair, 

 skin, flesh, blood, and bone, we should learn its Histology. 

 The consideration of the manifold changes undergone 

 in developing from the egg to the full-grown animal, 

 would be the Embryology of the horse ; and its Mor- 

 phology, the special study of the form of the adult ani- 

 mal and of its internal organs. 



Thus far we have been looking, as it were, at a steam 

 engine, with the fires out, and nothing in the boiler; 

 but the body of the living horse is a beautifully formed, 

 active machine, and every part has its different work to 

 do in the working of that machine, which is what we 

 call its life. The science of such operations as the 

 grinding of the food in the complex mill of the mouth ; 

 its digestion in the laboratory of the stomach ; the pump- 

 ing of the blood through a vast system of pipes over 

 the whole body ; its purification in the lungs ; the pro- 

 cess of growth, waste, and repair; and that wondrous 

 telegraph, the brain, receiving impressions, sending 



