68 



The Rot in Sheep. 



the capillaries of the chylo-poietic viscera ; and the nutritive 

 materials of the food— apart from the chyle — which enter these 

 vessels from the intestinal canal are consequently not conveyed 

 at once into the general circulation, but are first subjected to the 

 action of the liver. " The blood in the portal vein differs 

 materially from venous blood in other parts of the body. Among 

 other things it is deficient in fibrine and albumen, but contains 

 more red corpuscles, and about twice as much fatty matter; 

 and in animals fed on farinaceous substances, more sugar" 

 (Kirkes). " And as, after having passed through the liver, the 

 fibrine is increased, and other no less important changes 

 wrought in the blood, there seems no reason to doubt that this 

 fluid has been both depurated of materials which would be 

 injurious, and assimilated more to the character of ordinary blood. 

 Apart from this, fatty matters especially would appear to be 

 elaborated within the gland, either from saccharine substances or 

 from albuminous compounds; for even when no fat can be de- 

 tected in the blood of the vena porta?, that of the hepatic vein 

 contains it in considerable amount " (Carpenter). 



In the comparatively recent experiments also of Dr. Harley 

 and Professor Sharpey communicated to the Royal Society, it 

 has been shown that even when the portal blood is devoid of sugar, 

 as in a fasting animal or one fed solely on flesh, sugar is found 

 in the liver, having been formed therein. We may here observe 

 that, chemically considered, starch, sugar, and fat, are allied 

 substances, being all hydro-carbonates, sugar containing a 

 somewhat greater quantity of carbon than starch, but less than 

 fat. 



The bile, as may be easily supposed from the foregoing pre- 

 mises, is a very complex fluid, and has a more important office to 

 perform in the assimilation of the food than in the carrying away 

 of materials which impair the purity of the blood. Entering the 

 intestine — duodenum — by means of the main biliary duct, it com- 

 mingles with the chymous mass — the digested food — as this 

 passes from the stomach ; and, assisted by the fluid secreted by the 

 pancreas, which is also present in the intestine, effects the chyli- 

 fication of the chyme. The chyle thus formed is absorbed by the 

 lacteals, and carried by them into the general circulation. In the 

 process of chylification a portion of the bile — the colouring mat- 

 ter in particular — as excrementitious material is moved onwards 

 with the unassimilated parts of the chymous mass and ejected as 

 f;rculent matter. That portion of the fluid, however, which is 

 employed in effecting chylification, among other things, acts on 

 the amylaceous matter — starch of the food — and converts it into 

 sugar, ready to be taken up by capillary blood-vessels. The 

 presence of bile in the intestines is also said to cause a more 



