CONCENTRATION or ANTIBODIES 147 



increase, and, indeed, one would not expect that they would, since 

 in the actively immune animal the presence of antibodies is the excep- 

 tion and not the rule. The results here are typical of all of our results. 

 In four passively immune cats this same increase in the concentration 

 of the agglutinins in serum, neck lymph, and the thoracic lymph was 

 noted. In two of the four cases the concentration in the neck lymph 

 and the thoracic lymph was equal, in the remaining two of the four 

 experiments the concentration in the thoracic lymph was greater 

 than that in the neck lymph. There appears on the whole to be a 

 tendency for the concentration of the agglutinins in the thoracic and 

 the neck lymph in the passively immune animals to run more nearly 

 parallel than in the actively immunized animals. 



DOGS. Passive immunity produced in dogs in the manner 

 described yields exactly similar results; namely, the concentration in 

 agglutinins of the serum, neck lymph, and thoracic lymph can be 

 greatly increased. The concentration of the agglutinins in the peri- 

 cardial fluid, cerebrospinal fluid, and the aqueous humor is no higher 

 than in the normal animal. 



In one of three passively immunized dogs the concentration in the 

 neck lymph and thoracic lymph was equal; in the other two the 

 thoracic lymph was much higher. The fact that 50 per cent of our 

 passively immunized cats and 33 per cent of the passively immune 

 dogs showed an equal concentration of the agglutinins in the thoracic 

 and the neck lymph may be significant, for the percentage of 

 such findings in the actively immune animals is 14 per cent for 

 the dogs and 16 per cent for the cats; but much more extensive 

 experimentation is necessary before any reliance can be placed on 

 these results. 



In order to determine the relative rapidity with which these anti- 

 bodies pass from the blood into the lymph the following experiment 

 was made. A dog was anesthetized and rendered passively immune 

 by the withdrawal of 300 c.c. of blood from the femoral artery and 

 the injection of 300 c.c. of blood and serum from a typhoid immune 

 dog. Small samples of blood were drawn at stated intervals, as 

 were also samples of neck lymph. Thoracic lymph, pericardial 

 fluid, cerebrospinal fluid, and aqueous humor were collected at the 

 end of the experiment. All of the fluids except the thoracic lymph 



