184 PRACTICAL HISTOLOGY [XXIII 



mount in balsam. The cells show a stained outer 

 limit, and a stained network or scattered particles in 

 the cell ; the glycogen forming a large part of the cell 

 is unstained. Note the interlobular bile ducts, which 

 commonly are obvious in the rabbit, and the passage of 

 the cell-columns of one lobule with those of the neigh- 

 bouring lobules (cp. 2). 



5. Scrape a small portion of fresh liver, and observe 

 the pale, granular, hepatic cells; often containing fat 

 globules. 



6. Test for iron, (a) Place sections of liver 1 in a mixture of 

 equal parts of 2 p.c. hydrochloric acid, and 2 p.c. potassic ferro- 

 cyanide, warm for a few minutes, wash and mount in balsam. 

 Particles containing iron or certain simple organic compounds 

 of iron will be stained deep blue. (Prussian blue reaction.) 

 (b) Mount the section in a strong solution of sulphide of 

 ammonium, the particles containing iron will be stained black 

 (ferrous sulphide reaction). 



DEMONSTRATIONS. 



1. Section of mammalian liver to show the bile 

 capillaries. (Liver treated by Golgi's potassium bichro- 

 mate and nitrate of silver method. Cp. p. 240.) Note 

 the black lines indicating the bile capillaries, they form 

 a network passing over the surfaces of the cells. 



2. Section of rabbit's liver containing glycogen 

 (osmic acid). The glycogen is represented by the 



1 In a chloroformed animal inject diamine of toluylen into a vein, 

 in 4 or 5 hours cut out the liver and preserve in alcohol. Iron-con- 

 taining particles will be present in the centre of the cell-columns of 

 the liver. 



