184 THE MUSCLES. 



which, he asserts, facilitates the study of anatomy in a surgical point of 

 view). 



B. Peepakation. — We will limit ourselves to some general remarks on the following 

 points : 



Choice of a subject.— It there is for disposal a certain number of subjects from among 

 which it is possible to make a selection, the preference should be given to those thiit 

 have the muscular system best developed ; not that large, soft, lymphatic horses with 

 enormous masses of muscle should be chosen, for these animals are always less 

 convenient than small or middle-sized, well-bred horses. Asses and mules, when very 

 emaciated, answer well for the preparation of the muscles. 



Position of the subject. — It is necessary to place the subject, immediately after death, 

 in a convenient position, in order that the cadaveric rigidity may set in while it is in that 

 attitude. Without this precaution, the various parts of the body may assume an incon- 

 venient shape or direction, and all attempts to amend them will prove almost unavailing, 

 particularly in the larger animals. 



Three principal positions may be given to subjects : 



1. The animal is in the first position when it is placed on its back, the four ex- 

 tremities in the air, and maintained in that posture by means of long cords passed 

 round the pasterns and fixed to the movable rings which terminate the extremity of the 

 four bars of the wheeled-table on which the subject is laid. The head should be beyond 

 the end of the table and rest upon a stool. The animal should always be placed in such 

 a manner that the head be opposite the fore- part of the table, so that the movements of 

 the pole or shaft be not impeded during the displacement of the apparatus. In order 

 that the neck be not twisted to the right or left, in attaching the fore-limbs the subject 

 should be raised so that the withers rest lightly on the table. According to the bulk of 

 the animal and the length of the bars, the ropes should be passed around either the 

 pasterns, above the fetlocks, or even above the knees. 



2. To place the animal in the second position, it is turned on the belly, the two 

 thighs flexed, the extremities carried beyond the table, and the head fixed between two 

 bars by means of a rope passed under the zygomatic arches. 



3. The subject is in the third position when it rests on its side. 



Buhs to be observed during the preparation. — 1 . By no means, if possible, remove the 

 skin from the regions to be dissected until quite ready to begin the dissection. If this is 

 impossible, then take the precantion of enveloping these regions in damp cloths, or in 

 the animal's skin, to prevent desiccation of the aponeuroses and tlie superficial muscles. 



2. To dissect a muscle, it is necessary to remove the aponeuroses or the other 

 muscles which cover it, the cellular tissue enveloping it, and the fat, glands, vessels, and 

 nerves lodged in the neighbouring interstices. The aponeuroses should be removed in 

 shreds by making them very tense with the forceps, but without raising them, and 

 causing the blade of the scalpel to glide between the fibrous and muscular surfaces, 

 keeping it always parallel to these two planes. The covering muscles should not be 

 entirely excised, but ought to be out through the middle, across their fibres, and the 

 ends thrown back ; in this way it is always possible to replace a muscle by bringing the 

 two portions together ; the study of its relations is then much more easy. The cellular 

 tissue is got rid of by removing it with the forceps, and carrying the edge of the scalpel 

 in the re-entering angle formed by the cellular layer and the surface of the muscle. 

 This method also suffices for removing aponeuroses when they are slightly adherent to 

 the muscular fibres. But when they give attachment to these by their under face, as 

 may be noticed in the external scapular aponeurosis, it is necessary to have recourse to 

 the method indicated above. To remove fat, glauds, etc., scissors will be found very 

 advantageous. 



Order to follow in preparing all the muscles of the same subject, and to derive most 

 advantage therefrom. — 1. Place the subject in the first position, and commence by study- 

 ing the muscles of the inferior abdominal region. Then excise them, leaving the posterior 

 extremity of the great pectoral muscle, the prepubio tendon, and the crural arch intact. 

 The abdominal cavity having been emptied of the viscera it contains, dissect and study 

 successively the diaphragm, the internal crm'al region, except the deep muscles, the 

 sublumbar region, the femoral and posterior crural regions, the superficial muscles of 

 the inferior cervical region, and the pectoral region. 



2. After detaching for future use one of the anterior limbs, the animal is placed in the 

 second position, and one after another may be dissected the muscles of the ear, those of 

 the superior cervical region, the croup and costal regions, except the triangular muscle, 

 and the spinal region of the back and loins. 



