SECTION V. 



AGGLUTININS AND ANTIAGGLUTININS. 



It is not my wish to dwell at any length upon the agglutinins and 

 antiagglutinins. They are frequent in haemolytic sera, the serum of 

 one animal generally agglutinating the blood corpuscles of another ; thus 

 fowl serum has a powerful agglutinating action upon the corpuscles 

 of the rat and rabbit (as observed by Bordet, X. 1898), this action 

 depending upon the presence of normal agglutinins in the serum of the 

 fowl. Powerful agglutinins are also present in the venoms of serpents. 

 The agglutinins may or may not be specific. Where artificially produced 

 they belong to the latter category, as also when they develope in conse- 

 quence of disease. If an animal is immunified against the blood of 

 another, it developes agglutinins which act more or less powerfully 

 on the foreign corpuscles. The agglutinins may coexist with other 

 antibodies in a given serum, the complexity of serum in this respect 

 appearing to be unlimited. There may moreover be several agglutinins 

 present at once in a serum. Thus Myers (14, vii. 1900) found that 

 a precipitating antiserum for sheep's globulin, obtained from a rabbit, 

 agglutinated the washed blood corpuscles of the sheep as well as those 

 of the fowl. That the agglutinins which acted on the two kinds of 

 corpuscles were different was shown by adding one kind of corpuscles 

 to the antiserum until it ceased to agglutinate them, it being then 

 found that it was still capable of agglutinating the other kind ; the 

 same result following a reversal of the order, in which the corpuscles 

 were subjected to the action of the serum. 



The agglutinins have however received chief attention from bacterio- 

 logists, their presence in the serum in certain infective diseases, and 

 after recovery, being as is well known a valuable aid in diagnosis. The 

 agglutination test is applicable moreover to a large number of germs 

 against which animals may be immunified. As in the case of the 



