VI 



day and then slowly decreased. Similar observations 

 are made by Durham and Neisser. 



The leading features of this agglutinin curves are 

 thus very like those earlier observed for the other an- 

 tibodies, mentioned in the introduction, and those descri- 

 bed by Levin in the following paper in the case of 

 immunisation against B. coli. 



The fluctuations during the production of a series of 

 antibodies have now been examined, viz the tetanus, 

 diphtheria and botulismus antitoxin, rennin antitoxin, 

 the hsemolysins, typhoid, cholera and coli agglutinin, 

 and upon different animals, horses, goats, rabbits and 

 guinea-pigs. Among the great variations in the immu- 

 nisation against these very different toxic matters, it 

 seems possible to pick out a rule with a rather general 

 applicability, viz. that the course of the immunisation 

 has the same type, as was found by Brieger and Ehrlich 

 in their first experiments with tetanus. 



It might then be the most practical way to attack 

 the problems involved in the production of the anti- 

 bodies from a thorough study of for instance the agglu- 

 tinins, which can so readily and accurately be measured 

 in test tubes alone, and from such facts proceed to the 

 study of other antibodies. 



The agglutinin curves seem to be most like those 

 observed in the case of diphtheria antitoxin. In the com- 

 parison of their details the following is to be noticed. 

 The fall, which is always very pronounced after an 

 injection of diphtheria toxin, is very insignificant in the 

 agglutinin curves and often not at all to be demonstrated. 

 The second phase on the contrary corresponds in the 

 two cases; and the maximum occurs at the same time, 

 about the 9th day after the injection. A few times th is 

 was observed as early as the 7th day, some times this 



14 



