86 COLLECTED STUDIES IN IMMUNITY. 



complements circulating in the serum do not cause the formation of 

 autoanticomplements. Confirmation of this view is furnished by 

 the fact that even in animal species possessing identical complements 

 it is impossible to produce anticomplements by means of serum 

 injections. Thus, neither sheep when injected with goat serum, nor, 

 conversely, goats when injected with sheep serum produce any anti- 

 complement, for these two species manifest an extensive similarity 

 in their complements as well as in other serum constituents. 



When, then, in spite of this rule, we find that in our case auto- 

 anticomplements have developed, only one explanation remains: 

 that one or the other complement present in the goat serum, although 

 related, is not identical with the complement of the rabbit. If we assume 

 that a certain goat complement possesses the same haptophore group 

 as does a certain rabbit complement, but that it differs in the rest of 

 its constitution, then the assumption that identical complements do not 

 form anticomplements will not apply. In this case, by means 

 of the haptophore group of the particular receptor of the rabbit cell, 

 a foreign complex would be anchored which exerts a sufficient stimulus 

 on the cell to cause an increased production and thrusting off of the 

 corresponding side-chains which can functionate as anticomplements. 



We shall have to assume that the particular goat complement, 

 because of its identical haptophore group, can be anchored at the 

 same places as the idiocomplements with the same haptophore group. 

 Foremost among these places we may consider the complex receptors 

 which possess two haptophore groups (amboceptors). In this case, 

 contrary to what we usually observe, the thrusting-off of an amboceptor 

 would be effected through the anchoring of its complementophile group, 

 and we should then have additional proof for our view that the com- 

 plex receptors possess two binding groups. 



In any case it would seem to be of the greatest importance to gain 

 an insight into the conditions governing the disappearance of the 

 idiocomplements. That they can be caused to disappear through 

 injection of anticomplements produced by immunization follows as 

 a matter of course from our definition of anticomplements. This, 

 however, occurs only under artificial experimental conditions and 

 so possesses but little significance pathologically. Of considerable 

 importance for these occurrences under natural circumstances are 

 the vital conditions governing the disappearance of complement 

 through internal metabolic processes. The origin of the autoanti- 

 complements as it has just been presented by us surely belongs here, 



