286 Anatomy of the Rabbit. 



close to the inguinal ligament. An ordinary single knot may be 

 placed on the ligature, but must be left loose until the cannula 

 is inserted. By grasping the bare edge of the artery at about 

 2 cm. from the ligament, the operator may make a V-shaped 

 incision in the vessel with fine scissors. The tips of the scissors 

 are directed toward the ligament. The incision must be clean-cut, 

 and care must be taken not to cut more than half-way through the 

 vessel. By taking up the little angular flap with the fine forceps, 

 the cannula may be worked, into the vessel and pushed well down 

 into it beyond the inguinal ligament. The knot is then tightened 

 by a gentle even pull on the ends of the thread. The knot should 

 never be pulled very tight or doubled. 



At the moment when the cannula is securely fastened into the 

 vessel, the clamp is to be removed from the connecting tube and 

 the fluid allowed to run in. At the beginning of the process a little 

 care in arranging the animal will be amply rewarded by conven- 

 ience in dissection. The hind limb on the side opposite the in- 

 cision should, be drawn backward. The front limbs should be 

 drawn apart, so that the breast is well exposed, and held in this 

 position by a thick cord, or, better, a stout flexible wire, passing 

 around, the back of the animal. The body should be turned 

 slightly to the operator's left. 



The animal is sufficiently embalmed in two hours. About 

 eight animals may easily be kept on the table by one operator, 

 provided he has at his disposal a sufficient number of cannulae, 

 one for each specimen, since the first may be taken off the appar- 

 atus after the eighth has been put on. After some practice the 

 number can be greatly increased. 



Since small difficulties frequently occur in the process, especially 

 in placing the cannulae and in keeping them clear ot obstruction, 

 a number of points may be mentioned which indicate to the oper- 

 ator just how the operation is succeeding. The entrance of the 

 cannula into the artery, in the first place, is usually accompanied 

 by a slight rise of blood into its tip. General muscle contractions 

 in the recently killed animal are a safe indication of uniform flow 

 of the fluid to these and also other parts of the body, and no clogging 

 of the vessels need be feared. The fluid may usually be observed 



ming in the cannula, and, of course, falling in the reservoir. 



