LAMENESS. 275 



may result in lesions of internal parts, frequently the most serious and 

 obscure of all in their nature and effects. 



The horse is too important a factor in the practical details of human 

 life and fills too large a place in the business and pleasure of the 

 world to justify any indifference to his needs and physical comfort 

 or neglect in respect to the preservation of his peculiar powers for 

 usefulness. In entering somewhat largely, therefore, upon a review 

 of the subject, and treating in detail of the causes, the symptoms, the 

 progress, the treatment, the results, and the consequences of lameness 

 in the horse, we are performing a duty which needs no word of 

 apology or justification. The subject explains and justifies itself, 

 and of its own vindication and illustration, if any are needed. 



The function of locomotion is performed by the action of two prin- 

 cipal systems of organs, known in anatomical and physiological 

 terminology as passive and active, the muscles performing the active 

 and the hones the passive portion of the movement. The necessary 

 connection between the cooperating parts of the organism is effected 

 by means of a vital contact by which the muscle is attached to the 

 bone at certain determinate points on the surface of the latter. 

 These points of attachment appear sometimes as an eminence, some- 

 times a depression, sometimes a border or an angle, or again as a 

 mere roughness, but each perfectly fulfilling its purpose; while the 

 necessary motion is provided for by the formation of the ends of the 

 long bones into the requisite articulations, joints, or hinges. Every 

 motion is the product of the contraction of one or more of the 

 muscles, which, as it acts upon the bony levers, gives rise to a move- 

 ment of extension or flexion, abduction or adduction, rotation or cir- 

 cumduction. The movement of abduction is that which passes from 

 and that of adduction that which passes toward the median line, or 

 the center of the body. The movement of flexion and extension are 

 too well understood to need defining. It is the combination and 

 rapid alternations of these movements which produce the different 

 postures and various gaits of the living animal, and it is their inter- 

 ruption and derangement, from whatsoever cause, which constitute 

 the pathological condition of lameness. 



A concise examination of the general anatomy of these organs, how- 

 ever, must precede the consideration of the pathological questions 

 pertaining to the subject. A statement, such as we have just given, 

 containing only the briefest hint of matters which, though not neces- 

 sarily in their ultimate scientific minutiae, must be clearly compre- 

 hended in order to acquire a symmetrical and satisfactory view of the 

 theme as a practical collation of facts to be remembered, analyzed, 

 applied, and utilized. 



It was the great Bacon who wrote : " The human body may be 

 compared, from its complex and delicate organization, to a musical 

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