JOINT ACTION OF SEVERAL AMBOCEPTORS. 



621 



had been treated with sensitized ox blood previously digested with 

 horse serum does dissolve guinea-pig blood in conjunction with 

 horse serum less rapidly and less actively than does native (i.e., 

 untreated) ox serum. We should imagine that, according to the 

 views of Bordet and Gay, the ox serum in this case would have 

 been completely exhausted. Be this as it may, the fact remains 

 that the one dicisive experiment has not been made. 



II. 



In our experiments, therefore, we first sought to fill this gap. 

 We made use of 5% suspensions of guinea-pig blood-cells, which, 

 of course, were washed free of serum. The ox serum was inact- 

 ivated by half an hour's heating to 53-54. In all the tests the 

 mixtures were brought up to the same volume with physiological 

 salt solution, and this volume was never less than 2 cc. nor more 

 than 2.3 to 2.5 cc. The titration of the horse serum is shown in 

 the following table. 



TABLE I. 



After this to each 1 cc. 5% suspension guinea-pig blood was added 0.35 cc. 

 horse serum, i.e., sufficient to surely activate, and the mixtures digested at 

 37 for one hour. A test of the decanted fluids showed that the active principle 

 had been bound by the blood-cells. (See Table II.) 



The blood sediments which had thus been treated with horse serum were 

 next digested for one hour at 37 with decreasing amounts of inactive ox 

 serum. No haemolysis occurred. The tubes were then centrifuged and the 

 decanted fluids digested with 0.35 cc. horse serum plus the sediment from 

 1 cc. 5% guinea-pig blood. (Series A.) 



