STUDIES ON ILEMOLYSINS. 109 



the least affected by our anti-immune body. It may be that an entirely 

 different receptor apparatus is present in the goose and that this 

 effects a combination with different haptophore groups which leads 

 to the formation of immune bodies of entirely different character. 



Our further experiments concerned themselves with the action 

 exerted by our anti-immune body on immune bodies derived from 

 rats, guinea-pigs, and dogs by treatment with ox blood. We found 

 that the anti-immune body exerted a distinct protective action against 

 all three sera, but that this was less strong than that against the 

 immune body of the rabbit. The protection was least against the 

 serum of the rat, for it did not even suffice to absolutely protect against 

 one-half or one-third of the fatal dose. Complete solution ensued 

 in the presence of 0.3 cc. anti-immune body even when only double 

 the usual solvent dose of immune body was employed. This indicates 

 that this serum contains a relatively large amount of the non-neutraliz- 

 able types of immune bodies, in any case an amount far greater than 

 is contained in the rabbit serum. In the guinea-pig the case is very 

 similar, the proportion of double the solvent doses being as 1:3. 

 The nearest approach to the ratio as found in the rabbit is seen in 

 the serum of a dog treated with ox blood. In this it required six 

 times the usual solvent dose to effect complete solution in the presence 

 of the anti-immune body. 1 



All this leads to the conclusion that in the immune serum of 

 these three species the cytophile group of certain portions is identical 

 with the cytophile group of certain immune bodies in the rabbit. 

 Certain particular groups of the ox blood-cells therefore must fit 

 equally into the receptors of these different animals. In view of 

 this fact, the entire absence in the goat of that portion of immune 

 body which can be neutralized by the anti-irnmune body is of special 

 interest. As already stated, we are here dealing with an exception 

 which is connected with the impossibility of autolysin formation. 



We must therefore conclude that in conformity with our assump- 

 tion,, the immune bodies formed in any single case by treating various 



1 It is perhaps of interest to know that the immune bodies derived from 

 these three species (guinea-pig, rat, and dog) differed in their behavior toward 

 goat blood-cells. It was found that while the immune bodies of guinea-pigs 

 and rats acted on goat blood, those of the dog did not. This indicates that 

 the dog, in contrast to rabbits, guinea-pigs, and rats, possesess no receptors 

 for the groups (3 of the diagram, Fig. 1) common to the blood-cells of oxen 

 and goats. 



