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 torunin. 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 of 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 
running in the cannula, and, of course, falling in the reservoir. 
