SECRETION AND EXCRETION. 128 
part in the digestive process, it is decomposing matter 
filtered from the blood, and, if not cast out of the system, 
Fia. 92.—Liver of the Dog, F, F; D, duodenum and intestines; P, pancreas; 1, 
spleen; e, stomach; jf, rectum; R, right kidney; B, gall-bladder; ch, cystic 
duct; F, lobe of liver dissected to show distribution of portal vein, VP, and 
hepatic vein, vh; d, diaphragm; VC, vena cava; C, heart, 
produces jaundice. It is reabsorbed by the lacteals, but 
is finally discharged by oxidation through the lungs. In 
animals of slow respiration, as Crustaceans, Mollusks, 
Fishes, and Reptiles, fat accumulates in the liver. “ Cod- 
’ I ’ 
liver oil” is an example. 
The great Excreting Organs are the lungs, the kid- 
neys, and the skin; and the substances which they re- 
move from the system—carbonic acid, water, and urea— 
are the products of decomposition, or organic matter on 
its way back to the mineral kingdom.” Different as these 
