104 CONDITIONS OF ANTIBODY PRODUCTION 



There is nothing surprising in that when we consider how different 

 persons vary in constitution and susceptibility. Again, it is not 

 uncommon to find auto-agglutinins in human blood i.e., sub- 

 stances which agglutinate human red corpuscles. When this is 

 the case, it is found that these agglutinins have no action on the 

 red corpuscles of the persons from whom the serum is taken, but 

 only on those of other individuals ; the stroma of the corpuscles 

 cannot act as an antigen to the cells with which it comes normally 

 into contact. (The way in which these auto-agglutinins are 

 called into existence, and their meaning, if any, or use in the 

 economy, are still unexplained.) 



The existence and mode of formation of the secondary anti- 

 bodies i.e., the antibodies to antibodies point in the same 

 direction. Thus, if we inject typhoid bacilli or their proteid 

 constituents into rabbits or other animals, the specific antibody 

 the agglutinin is produced, and accumulates in the blood in con- 

 siderable amount, but it does not produce anti-agglutinin. If, 

 however, we inject this serum into an animal of another species, 

 and preferably one far removed from the first zoologically, the 

 production of anti-agglutinin occurs. The agglutinin produced in 

 any one species of animal must have, in addition to its peculiar 

 clumping properties, the general constitution of a proteid charac- 

 teristic of that animal, and hence be devoid of the power of 

 forming antibodies whilst in the blood where it was produced. 

 Similar phenomena occur in the production of other hgemolysins 

 (amboceptor), which will be referred to subsequently. 



With regard to the second criterion the possession of hapto- 

 phores which fit the receptors of the protoplasm of the animal 

 into which it is injected it is only necessary to say that, as far 

 as can be traced, the substances which produce antibodies do, as a 

 matter of fact, disappear from the blood of the animal in a short 

 time a few hours or days. As has been pointed out, the converse 

 of this is not necessarily true ; the toxin may disappear from the 

 blood, and yet no antitoxin be formed, as in the case of tetanus 

 toxin in scorpions. Here we have assumed that the scorpion 

 contains naturally a proteid with a haptophore closely allied to 

 that of tetanus toxin, that the toxophore of the latter is without 

 action on the cell with which it is linked, and that the latter can 

 use the former as pabulum in the same way as it uses the 

 molecules of normal occurrence in its blood. 



The third criterion is that the proteid molecule shall not be 



