462 Drs. Herring and Simpson. Relation of the [May 31, 



distends the blood-vessels and increases the amount of injection mass in the 

 liver cells — not by the appearance of more canals, but by the widening of 

 vacuole-like spaces on their course. The intracellular channels of the rat's 

 liver appear, therefore, to be very easily injected ; in fact, it would seem 

 difficult to avoid injecting them. 



We are able to confirm the observations of the brothers Fraser on the 

 frog ; a pressure of 20 mm. Hg at the bulbus aortas injects the cells of the 

 liver so as to show fine channels ending in vacuole-like dilatations. We are 

 unable to find any injection in the nuclei. Carmine gelatine is not, however, 

 a very suitable injection for cold-blooded animals. 



Four rabbits were injected ; all show the fine intracellular channels 

 described by Schafer. Three were injected from the aorta with pressures 

 varying from 100 to 120 mm. Hg ; one from the portal vein with 30 mm. 

 pressure. But in this latter experiment there was considerable leakage from 

 rupture of one of the large branches of the portal vein, and the pressure 

 in the liver must therefore have been less than that recorded by the 

 manometer. 



Two guinea-pigs were injected with aortic pressures of 100 mm. and 

 120 mm. Hg respectively. The injection mass did not run well in the first 

 experiment, but the livers of both animals show intracellular injection. 



One hedgehog, injected from the aorta at a pressure of 120 mm. Hg, 

 shows the intracellular injection appearances ; there was a free flow of 

 injection mass from the inferior vena cava the whole time. In the only other 

 hedgehog tried the injection fluid did not flow properly, and the injection 

 failed, the vessels of the liver being incompletely filled. The injection mass 

 employed in this case had been made up a considerable time, and we have 

 found by experience that the best results are obtained with freshly prepared 

 material. 



In the dog, every injection shows the intracellular channels. In one 

 animal, a young one, a pressure of 100 mm. in the aorta gave injection 

 appearances throughout the cells of the liver. In another the injection was 

 made by the portal vein, the inferior vena cava having been opened in the 

 thorax and ligatured in the abdomen below the liver. Three hundred cubic 

 centimetres of Einger's solution, saturated with chloroform, was first perfused 

 at a pressure of 20 mm. Hg ; the carmine gelatine was then allowed to run 

 in, the inferior vena cava next ligatured, and a pressure of 20 mm. Hg 

 maintained during 10 minutes. Many of the liver cells contain carmine 

 gelatine, which has the appearance of being accumulated chiefly in rounded 

 masses as if in distended vacuoles. 



In one of the injections from the aorta, as already mentioned, the portal 



