56 



gland and the relation of the capillary network to the tubules of 

 the acini of the gland. 



LIVER. 



117. Liver. Pig. Picric alcohol ; collodion; sections fx. 

 Stain with hematoxylin and picrofuchsin. 



Study thoroughly the preparations illustrating the gross anat- 

 omy of the liver ; (a) position, {b) aspects, {c) lobes, (a?) the longi- 

 tudinal and transverse fissures, (^) the appearance of the liver sub- 

 stance as seen in section and the natural surface (covered by the con- 

 nective tissue capsule), (y) the indistinct lobulation. 



In studying the section of liver note the lobules separated by 

 connective tissue septa. Within the lobules recogn ize the intra- 

 lobular vein and the arrangement of the liver cells. In the inter- 

 lobular connective tissue will be found inter-lobular veins, inter- 

 lobular arteries, small bile ducts. Can you find intra-lobular blood 

 capillaries passing ofiF from the inter-lobular veips or entering the 

 intra-lobular veins ? Be sure you understand the course of the 

 blood and the origin and relations of the different vessels. What is 

 the relation of the liver cells to the blood capillaries and the bile 

 capillaries? Note well the structural appearance of the liver so 

 that you can distinguish it from other glands. The liver of the 

 pig has a large amount of connective tissue between the lobules, sep- 

 arating them completely ; hence their distinctness. 



118. Liver. Horse or Homo. Assigned for study. Potas- 

 sium dichromate or Krlicki's fluid ; paraffin ; stained with hema- 

 toxylin and picrofuchsin. 



Study carefully, identifying the parts and structures already 

 recognized in 117; compare with that preparation, noting the in- 

 complete isolation of the lobules, less inter-lobular connective tissue, 

 etc. Again consult the gross preparations, examining them in the 

 light of your present knowledge of the structure of the liver. 



119. Bile capillaries. Liver of ox. Demonstration. The 

 bile capillaries are gorged with bile, caused by physiological stasis 

 of bile in Texas fever. Note the fineness of the capillary network 

 and the relation of the capillaries to the cells. 



120. Glycogen. Demonstration. Liver hardened in abso- 

 lute alcohol ; paraffin ; sections stained with a solution of iodin ; 

 mounted in iodin-gum arabic. The glycogen is stained a yellowish 

 brown ; note its accumulation in one end of the cells (generally 

 toward the intra-lobular vein). Consult 



