INJECTION OF LIVEK. 225 



is conducted as follows : The animal (rabbit) having 

 been killed by bleeding, 1 the thorax is opened ; and 

 the pericardium being torn away, the heart is raised 

 and two thread ligatures are passed round the inferior 

 vena cava. One of these is tightened as near the 

 heart as possible, and then a snip is made in the vein, 

 so as to allow the blood to escape freely. Next, the 

 abdomen is opened, and the intestines 'and stomach 

 being gently drawn to the left side, the peritoneum 

 at the back of the abdomen is torn through, and a 

 ligature placed around the vena cava above the ac- 

 cession of the renal veins. The portal vein is then 

 found in the fold of peritoneum which connects the 

 under surface of the liver with the stomach, and a 

 ligature, in the noose of which the hepatic artery 

 may be included, having been passed round it near 

 the liver, a snip is made in the vessel, and the in- 

 jecting canula is tied in. This canula is now filled 

 by means of a pipette with warm salt solution, and 

 the supply tube (from the injecting bottle), having 

 been completely filled by the injecting fluid to the 

 exclusion of air in the same way as in the first in- 

 jection (p. 167), is slipped over the open end, and 

 the injection at once allowed to flow. As it passes 

 by the portal system of veins through the lobules of 

 the liver into the hepatic system, it forces whatever 

 blood is still contained in the bloodvessels of the 

 organ out into the vena cava, whence it can freely 

 escape into the thorax through the snip which was 

 there made in the vein. As soon as all the blood is 



1 In injecting the whole body it was recommended to kill the 

 animal by chloroform. This was for the purpose of having the 

 bloodvessels as much dilated as possible. When an animal is 

 killed by bleeding, the arteries contract very considerably, and, 

 remaining contracted some little time after death, offer a con- 

 siderable resistance at first to the passage of the injection, and 

 this may tend to spoil the result altogether. In the liver, how- 

 ever, the case is different, since it is not injected through arteries, 

 but through veins, which possess little contractility. Any blood 

 which remains in the vessels does not, so long as it remains fluid, 

 impede the passage of the injection, but it is driven before it. 



