90 THE INOCULATION OF ANIMALS AND THEIR STUDY. 



consists in injecting directly into the veins of the animal in 

 the direction of the circulation, the material to be inoculated. 

 Necessarily the material used must be a liquid, and the injec- 

 tion must be done slowly and witli precaution. Intravenous 

 injection is used especially in rabbits. The most convenient 

 point of injection is into the vein of the ear known as the 

 posterior auricular vein, which is easily penetrated from the 

 dorsal surface of the ear, where it lies superficial and 



FIG. 45. 



Kitasato's mouse-holder. 

 (Abbott.) 



Mouse-holder, with mouse in proper position. 



(Abbott.) 



imbedded firmly in the areolar tissue. For the pur- 

 pose of making these injections an ordinary hypodermatic 

 syringe with the needle used for injections in man is employed. 

 All that is required is that both syringe and needle be ster- 

 ilized. The mode of procedure is as follows : 



The rabbit is firmly held by an assistant. The ear chosen 

 is taken between the thumb and forefinger of the left hand, 

 and after washing and sterilizing the skin as thoroughly as 

 possible, the vein on the posterior edge of the ear is sought 



