456 STUDIES IN IMMUNITY. 



bovine serum may inhibit the hemolysis of guinea-pig corpuscles 

 rather than favor it.* We found indeed that alexin fixation of the 

 sensitized corpuscles takes place better when the fluid contains little 

 serum and a large amount of salt solution. For example, we pre- 

 pare two tubes, A and B, containing each 0.8 of a cubic centimeter 

 of salt solution plus 0.1 of a cubic centimeter of fresh bovine serum. 

 To A we add 0.3 of a cubic centimeter of bovine serum, 56 degrees, and 

 to both tubes 0.05 of a cubic centimeter of washed guinea-pig blood. 

 Conglutination and hemolysis occur in tube B in 30 and 40 minutes 

 respectively, in tube A in 40 and 60 minutes. In other words, the 

 heated serum is more inhibiting as serum than it is useful as sen- 

 sitizer, inasmuch as enough sensitizer is present in the fresh bovine 

 serum. But if, instead of employing in this last experiment fresh 

 intact bovine serum, we use serum that has been treated for about 

 10 minutes with an equal volume of guinea-pig blood, we obtain 

 directly opposite results. Under such conditions the addition of 

 a sensitizer is obviously necessary; and consequently we find that 

 although the heated bovine serum (0.3 of a cubic centimeter), as 

 serum, inhibits alexin fixation, it is necessary as containing sensi- 

 tizer. An experiment modified in this manner shows in tube B 

 no conglutination or hemolysis; the phenomena appear in A in 

 1J and 2 hours respectively. It would seem to us in view of so 

 many convincing facts that the thesis of Ehrlich and Sachs, which 

 supposes that the bovine amboceptor can unite with the cor- 

 puscles only in presence of the alexin, can no longer be admitted. 

 And what is more, we consider these authors' opinions on hemoly- 

 sis as purely theoretical, in so far as they bear on the existence 

 of a complementophilic group, partial anticomplements, multi- 

 plicity of complements, dominant and non-dominant complements, 

 and the like. 



SECTION II. 



VARIOUS EXAMPLES OF CONGLUTINATION AND THE MODE 

 OF ACTION OF THE CONGLUTININ. 



Conglutination always appears when the cells added to fresh 

 bovine serum or a mixture of heated bovine serum and alexin from 

 another animal are sufficiently sensitized and consequently in a 

 condition to absorb alexin. Whenever the normal sera employed 



* See the previous footnote criticising certain experiments of Sachs and Bauer. 



