DIGESTIVE SYSTEM. 40!> 



mesentery, urinary bladder, and lung the vessels can best In* 

 observed. 



37. New Formation of Capillaries. A rabbit, cat, or dog- 

 about five days old is killed with chloroform, and the abdom- 

 inal cavity opened. The mesentery or omentum majus is 

 stretched over a cork or cover glass, and fixed for from one 

 to two hours in Zenker's or Flemming's fluid. It is then 

 stained with hsematoxylin and eosin, or the Biondi-Ehrlich 

 mixture. 



38. Elastic Tissue of Blood-vessels. Tissues fixed in absolute 

 alcohol are stained in orcein or by Mallory's method. Henle's 

 fenestrated membrane may be isolated by dissecting the muscle 

 coats away from a medium-sized artery (femoral of dog). 

 Pieces of the membrane may be obtained and stained with 

 magenta. The membrane may also be isolated by treatment 

 with potassium hydroxide. 



39. The epithelium of the lymph sinuses can be demon- 

 strated by injecting a 0.1 per cent, silver nitrate solution with 

 a hypodermic syringe into the substance of the lymph gland. 

 After half an hour the gland is fixed in alcohol, and thick 

 sections are cut. 



40. The framework of the lymph gland, spleen, thyroid, and 

 adrenal may be isolated by digestion of frozen sections with 

 pancreatin (see Reticulum). 



41. It is instructive to study the elements of the lymph 

 gland, spleen, etc., in the fresh condition or by stains such as 

 methylene-blue. 



8. DIGESTIVE SYSTEM. 



42. Goblet cells may be well demonstrated by staining with 

 thionin. 



43. Auerbactis and Meissner's plexuses are stained by the 

 gold chloride method (59). 



44. The zymogen granules of the pancreas are colored red 

 in safranin or the Biondi-Ehrlich stain. 



45. Bile capillaries may be recognized by the following 

 methods : 



