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Lesson XXTT. 



LIVER, TRACHEA, LUNG, AND THYROID. 



(a) Liver Cells. 



Small ])iece.s from the liver of a cat were macerated for 24 lionrs 

 ill Uanvier's alcohol, and for 2 hours in 0.5% osiiiic acid. Tease 

 ill gum glycerine. 



Stud}'- under liiuli power. The liver cells are ])olyhe- 

 dr:d in form, and possess a distinct intracellular network. 

 Fat globules, stained black, may be seen in the cells. As 

 a ride a single spherical nucleus is found. Sketch several 

 as seen under high power. 



(b) Injected and Stained Liver. 



The I'ver of a i)ig was injected through the portal vein witli 

 Berlin blue, hardened in aicoiiol, stained in borax carmine, 

 embedded in paratfin, ami sectioned. Fix and mount in balsam. 



Study under high })Ower. Note that the gland is com- 

 posed of lobules, and injected interlobular branches of the 

 portal vein are seen between them. From these interlobu- 

 lar vessels capillaries pass into the lobule and unite in an 

 intralobular vessel, this emptving into a suldobular vein. 

 The liver cells ap2:)ear arranged in columns between the 

 capillaries. Sketch two of the lobules, showing the arrange- 

 ment of blood vessels and liver cells as seen under low 

 power. 



(c) Human Liver. 



Small pieces of a linman liver were liardened in mercuric chlo- 

 ride, embeilded in paratBn, and sectioned. The parattin was 

 removed from the sections with xylol ; tliey were then stained in 

 ha^matoxylin and eosin, dehydrated, and cleared in oil of berga- 

 mot. Mount in balsam. Study first under low power. 



In the human liver the hepatic lobules are separated 

 one from the other by only a verv small amount of inter- 



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