é^i 



aft. 5 ds. aft. 7 ds. 



After 17 days the titre already went back. 



Here we can see that, whereas of the series B three rabbits 

 distinctly lag behind, two of them reach as high a titre as the A 

 rabbits. Knowing (Uhlenhuth) that accidental failures in the preparation 

 of precipitinholding sera are not to be avoided, I should not wish to 

 draw any other conclusion from this than that a good formation of 

 precipitins is also possible with mixtures of serum and antiserum. 



I have also taken the following series of experiments. 



III. Rabbit 140 1 c.cm. horseserum intraperitoneal. 

 116 



So here too we find a rather important formation of antiserum 

 with rabbits, which, with the serum, had also got antiserum. 



IV. Rabbit 155 50 c.cm. antiserum '/looo + 2 c.cm. horseserum intraperit. 

 „ 156 30 „ „ +2 „ 



,, 157 10 ,, ,, -f- 2 ,, ,, ,, 



,, 158 ,, ,, + 2 ,, ,, ,, 



„ 159 15 „ „ +0 „ 



22* 



