132 E. R. HOSKINS AND M. M. HOSKINS 



the kidneys normally excrete nearly all of such injected pthalein 

 in four hours and very little appears in the bile at all (R own- 

 tree and Geraghty, '12). In mammals with tartrate nephritis, 

 or with their renal veins ligated, injected pthalein is excreted by 

 the liver (Underhill-Blatherwick, '14). 



All of the injected granular dyes appeared in the bile in con- 

 siderable concentration, and were not excreted by any organ 

 other than the liver, so far as determined. Siebel ('86) believed 

 that frogs and dogs receiving injections of carmine excreted 

 such particles through the liver, lungs, and tonsils, and Kiyono 

 ('14) and numerous other investigators have found that mam- 

 mals excrete lithium carmine through the kidney. 



In our experiments one sample of neutral red appeared after 

 injection in both the urine and bile, but its concentration in the 

 latter was more than eighty times as great as in the former. It 

 is believed that some of this neutral red w^as in solution and that 

 it was this part which passed through the kidney. The liver was 

 able to excrete the dye both in the dissolved and in the granular 

 form. Another sample of neutral red was excreted only in the 

 bile. 



Trypan blue after injection into dogfish collects in the hepatic 

 parenchyma and the cells lining the sinusoids. Wislocki ('17) 

 noted this also. It is excreted freely into the bile. In bony 

 fishes Wislocki found that trypan blue entered the bile, but 

 w^as not stored in the liver cells. He thought that it diffused 

 directly into the bile ducts from the blood-vessels but more 

 probably it passed through the liver cells too diffusely to be 

 seen under the microscope. 



In the dogfish there is present normally in the liver and bile 

 a very large amount of bile pigment (Fillet, '90) and after injec- 

 tion of trypan blue some of the masses of pigment seen in sec- 

 tions of the fiver contain both trypan blue granules and normal 

 pigment mixed together. These masses of mixed pigment may 

 be seen in the bile also, thus shov/ing that the excretion of par- 

 ticulate matter by the liver is a normal function and is not due 

 merely to experimental conditions. Experimenters are often 

 incUned to overlook the fact that results they obtain do not 



