308 OPERATIONS ON :\IUSCLES AND THEIK ANNEXES. 



the lateral caudal muscle on the side to which the tail is carried, 

 or upon one or both of the superior sacro-caudal muscles, the 

 elevators of the tail. As a rule, one incision only is necessary, 

 and it must be done subcutaneously, and in the subsequent treat- 

 ment, instead c f placing- the animal in pulleys, the tail must be 

 tied up to the surcingle on the side opposite to that of the opera- 

 tion ; or it may be allowed to hang down free. An experience on 

 our part of many years, has rendered us skeptical as to the success 

 of lateral caudal myotomy, a careful dissection of the tails of 

 animals affected with this deformity having- proved the existence 

 of an abnormality in the formation and development of the 

 caudal vertebrae which has been either the cause or effect of the 

 trouble. Operations jDerformed upon animals of this class have 

 not been usually followed by a satisfactory result. 



CEUEAL MYOTASE— CRURAL MYOTOI^IY. 



This affection is peculiar to bovines, and is a species of dis- 

 location, or displacement of the long vastus muscle — the 

 external ischio-tihial. It is a lesion which forms a very serious 

 impediment to the act of locomotion, by its disabling- effect upon 

 the movements of the hind leg-. 



The nature of crural myotase will be understood by those who 

 are f amihar with the anatomy of the region in cattle. With them, 

 the bicej)s femoris covers, in its normal position, the whole of the 

 coxo- femoral joint, in such a manner that its anterior border {a b), 

 Fig. 325, is situated in front of the joint. This border, from 

 the articulation to its lower end, forms a kind of tendon, (c) 

 closely connected with the aponeurosis of the fascia lata, (f) whose 

 divided layers surround the muscle, adhering intimately to its two 

 faces, the deep and the superficial. Passing over the trochanter 

 of the femur, with the assistance of a large mucous biirsa, the 

 biceps is quite thin, and is kept in position by an aponeurosis (c) 

 which partially covers the gluteus externus, and is united to the 

 fascia lata. 



"^Tien this aponeurosis is lacerated at a point on a level with 

 the hip joiat, while the leg is carried backward, in excessive ex- 

 tension, it is possible that the trochanter, thus carried forward, 

 may become engaged in the laceration, the biceps itself being- 

 hooked, as it were, behind the trochanter, and prevented from re- 



