THE LIVER AND BLOOD PIGMENTS. 339 



sociated: an important feature, since it removes the main ele- 

 ment of confusion from our path. Indeed, we can now easily 

 account for the retention of the greater part of bilirubin in the 

 liver, since we have at our disposal all the constituents for the 

 synthetic production within the portal capillaries of the hepatic 

 lobule of new haemoglobin, and particularly oxidizing substance, 

 brought there by the terminals of the hepatic artery. 



On examining, on page 329, the illustration from Piersol's 

 work, the distribution of the hepatic artery's terminal arterioles 

 or capillaries will be found to be unusual. Immediately above 

 the margin of the lobule i.e., where the portal or interlobular 

 vein breaks up into the capillary net-work of the lobule the 

 hepatic arteriole may be seen to open into the portal capillary. 

 The inference is obvious. The hepatic artery coming directly 

 from the cceliac axis, brings freshly oxidized Hood, i.e., oxidizing 

 substance, which, mixing freely in the narrow channels of the 

 lobule with the portal blood, at once groups bilirubin and iron, 

 and builds up all the hcemoglobin that the constituents present 

 (including what iron the splenic leucocytes and those from the 

 intestinal follicles have brought) allow. What bilirubin cannot, 

 owing to deficiency of either of the other constituents, be utilized, 

 becomes an excretory product; and with many others it enters the 

 hepatic CELL and is passed out with the bile. 



That deficiency of suprarenal-oxidizing substance can in- 

 crease the excretion of bilirubin has been repeatedly shown 

 herein. We may refer, for example, to the many forms of 

 acute poisoning and to the diseases attended with suprarenal 

 insufficiency in which there is increased excretion, either in the 

 urine or faeces, of haematoporphyrin, methaemoglobin, urobilin, 

 stercobilin, etc.: i.e., of some derivative of haemoglobin. 



We have referred to the hepatic cell as a miniature sponge. 

 This comparison, due to Berdal, is especially warranted, since 

 Schafer 16 noted the existence, within this cell, of canaliculi 

 which are in direct communication with the blood-capillaries. 

 Having injected carmine gelatin into the portal vein, the col- 

 ored substance filled this vessel and its subdivisions, besides 

 the canaliculi, but no other structure. It may, therefore, be 



18 Schafer: Journal of Physiology, Jan. 31, 1902. 



