448 STUDIES IN IMMUNITY. 



offered by Sachs and Bauer, and also offer further information on 

 the properties of the conglutinin. / 



No comparison between ordinary agglutinins and the conglutinin 

 is necessary. The two substances are evidently different. Agglu- 

 tinins have no need, for their action, of sensitized and alexinized 

 corpuscles, as does the conglutinin. In the experiment that has 

 just been mentioned, that is, the agglutination of sensitized bovine 

 corpuscles by fresh bovine serum, it is evident that we are not 

 dealing with an ordinary agglutinin. It is, however, interesting 

 to compare the development of the two phenomena by adding 

 bovine serum to two different species of corpuscles, one of which it 

 agglutinates and the other of which it conglutinates. Guinea-pig 

 and horse red blood cells, respectively, fulfill these conditions. 

 We may consider, in the first place, the agglutinating effect : to 

 two tubes containing 1 c.c. of salt solution and 0.1 of a cubic 

 centimeter of heated bovine serum, we add 0.05 of a cubic centimeter 

 of washed blood either from the guinea-pig or the horse. The 

 guinea-pig corpuscles are not markedly agglutinated, those of the 

 horse are rapidly agglutinated ; in this case we are dealing with an 

 ordinary agglutinin. We may then consider the conglutinin, that 

 is to say, in a similar experiment we may employ fresh bovine serum 

 instead of heated bovine serum. The horse corpuscles act just as 

 they do with heated serum : there is rapid agglutination of a similar 

 intensity, but no real conglutination appears.* The guinea-pig 

 corpuscles show no immediate agglutination any more than with 

 the heated serum. After 10 or 15 minutes conglutination appears 

 and the corpuscles collect into large clumps which gradually 

 hemolyze. It is to be noted that although a certain amount of 

 time is necessary for the fixation of the alexin, the clumping by 

 the conglutinin is much more marked than that by the ordinary 

 agglutinin. 



We may now consider Sachs and Bauer's objections: 

 (a) These authors consider Bordet and Gay's interpretation as 

 inacceptable since it necessitates the admission of a new substance, 



* This is due to the fact that they do not fix the alexin sufficiently, or, in 

 other words, to the fact that the bovine serum is not sufficiently sensitizing 

 for horse corpuscles. As Streng has shown in his memoir on the anticomple- 

 ment (Zeitschrift fiir Immunitatsforschung, vol. 1), horse corpuscles are perfectly 

 well conglutinated by fresh bovine serum when they have previously been sen- 

 sitized by a specific immune serum. 



