PRACTICAL DIRECTIONS. 447 



X. MUSCLES OF THE TAIL (p. 136). 



By removing the skin of the tail, all the muscles of the tail are 

 now easily seen. 



i, 2, 3, 4, 5 see 5, 6, 7, 8, 9, above (IX). 



6. The abductor caudse externus (p. 137, and Fig. 113, b; Fig. 



70, g)- 



7. The extensor caudae lateralis (p. 137, and Fig. 70, _/"). 



8. The extensor caudae medialis (p. 136, and Fig. 70, e). 



THE VISCERA. 



Kill the specimen with chloroform and inject with the five per 

 cent, formalin, or the mixture of formalin and glycerine, as for the 

 muscles. (It is an advantage if the preliminary examination of the 

 viscera can be done in a perfectly fresh, uninjected specimen; such 

 a specimen can be kept but a day or two, however. After one day's 

 examination the skin may be removed and the specimen placed in 

 two per cent, formalin; it will usually be fairly well preserved by 

 this, though the formalin is too strong to make the later dissection 

 pleasant. The specimen cannot be preserved in this manner unless 

 the skin is removed, and a sufficient quantity of formalin used.) 



PRELIMINARY EXAMINATION OF THE VISCERA. 



(In this preliminary examination the descriptions in the text need 

 not be read, except when this is specially directed.) 



Wet the hair along a line from the symphysis of the jaw to the 

 pubis. Part it and make a longitudinal incision through the skin 

 along the line. Make a transverse incision of the skin five centimeters 

 caudad of the xiphoid process and reflect the flaps. Incise the body 

 wall from the last rib to the pelvis along the same line as above and 

 also transversely. Reflect the flaps without injuring the ligaments of 

 the bladder. Make an incision through the pectoral muscles between 

 the first rib and the ventral attachment of the diaphragm and about 

 one centimeter from the median line. Make a second incision of the 

 muscles from the cranial end of the first incision along the angles of 

 the ribs to near the dorsolateral attachment of the diaphragm. Cut 

 the ribs and thoracic wall along these incisions with strong scissors ; 

 connect the two incisions at their caudal ends, and remove the lateral 

 thoracic wall thus circumscribed. Note the thoracic and abdominal 

 cavities, separated by the diaphragm. 



Note the following viscera in their fresh condition : 



A. In the abdominal cavity (without injuring anything) 



1. The liver, dark red and lobed, in the cranial part of the 

 cavity, lying against the diaphragm. 



2. The gall-bladder partly imbedded in the right median lobe. 



3. Displacing the liver craniad, the stomach is seen dorsad of its 

 left lobe. It may extend dorsad of the right lobe, its size depending 

 on the degree of distension. 



