INTRODUCTION. 9 



attached, very gentle pressure should then be exerted on the 

 plunger, until the blue solution appears in the lacteals. To 

 inject all the lacteals it is necessary to insert the cannula into 

 the wall of the intestine at a dozen different places. To fill 

 the thoracic duct, injection may be made into the large 

 lymphatic gland lying at the point where the converging 

 blood-vessels of the mesentery meet. The best solution for 

 injecting the thoracic duct is made by dissolving 7 gm. of 

 gelatin in a warm Berlin blue solution (4 gm. of Berlin 

 blue to 100 c.c. water). This should be filtered through a 

 single layer of absorbent cotton and then injected while still 

 quite warm. In all cases injections to fill the lymphatics 

 must be warm and must be pushed in very slowly. These 

 lymphatic injections are best preserved by injecting the 

 trachea and intestine with 95% alcohol and immersing the 

 cat in a jar of 70% alcohol. 



Preparation of a Mammal for Dissection of the 

 Muscles, Peripheral Nerves and Viscera. The simplest 

 method is to anesthetize the animal as before described and 

 then remove the skin, taking great care to avoid cutting 

 away the superficial muscles. The cannula should be 

 pushed through into the trachea and 100 c.c. of 15% for- 

 maline injected to fill the lungs. An equal amount of 

 formaline should be injected into the stomach through a 

 glass tube pushed down the esophagus. The same quantity 

 of formalin should be injected at two or three different 

 places into the intestines by making a median incision into 

 the abdominal wall and pulling out a loop of the intestine 

 into which the cannula may be thrust. The specimen is 

 then to be immersed in a jar of 5% formalin. A better 

 method is to inject into the carotid artery 200 c.c. of glyceri- 

 nated formalin (water 140 c.c., glycerin 30 c.c., formalin 

 30 c.c.), and half that amount into the intestine and trachea. 

 The specimen may then be preserved in 5 % formalin. 



