58 TECHNIC OF ANIMAL INOCULATION 



3. A small roll is placed under the neck of the animal, to render the 

 operative area tenser and more easily accessible. 



4. A few drops of ether may be given by an assistant, although one 

 soon learns to expose the vein quickly and there is practically no pain 



FIG. 29. A DISSECTION OF THE NECK OF A GUINEA-PIG TO SHOW THE RELATIONS 



OF THE EXTERNAL JUGULAR VEIN. 



The skin has been turned aside and the superficial fascia and fat removed; the 

 position of the vein is well shown and is readily exposed by a small and superficial 

 incision. 



after the skin has been incised. If anesthesia is employed, it should be 

 just sufficient to overcome the struggles of the animal. 



5. The assistant is directed to hold the head backward in the med- 

 ian line. 



