DEMONSTRATION OF SPECIES DIFFERENTIALS 503 



pigs depended upon the chemical relationship between the substances used 

 for sensitization and for reinjection, irrespective of the species of the plant 

 from which the substances had been obtained. Thus, for instance, gliadin 

 and hordein, although they occur in seeds of different species, could not be 

 differentiated by means of anaphylaxis, because their chemical structure was 

 similar. Corresponding results were obtained with other substances resem- 

 bling albumoses in their reactions, which likewise were isolated from seeds ; 

 however, these substances were not, in all probability, split products of pro- 

 teins, because real albumoses or peptones seem to lose their power to sensitize 

 the guinea pig. With these materials from seeds, bcause of their solubility 

 in water, anaphylactic reactions could be obtained much more readily than 

 with the above mentioned alcohol soluble substances. The tests indicated that 

 these albumose-like substances are quite distinct immunologically from the 

 alcohol soluble substances, although both occur in the same kinds of seeds. 

 A relative overlapping of reactions in experiments was apparently due to 

 impurities, it being impossible to separate completely the first and the second 

 type of substances. 



Wells and Osborne concluded, then, that the specificity in the anaphylactic 

 reaction depends primarily not on the biologic origin, but on the chemical con- 

 stitution of the substances used for sensitization and the production of shock. 

 But, the chemical constitution furnishes the basis for the biological specificity, 

 and biological specificity depends upon the constitution of tissue constituents, 

 and there should therefore be expected a correlation between the chemical 

 constitution of plant proteins and the systematic position of the plants in 

 which these substances originated. When, in the case of these plants substance- 

 specificity was prominent, whereas species-specificity was not manifest, it 

 may be assumed that besides the biologically important seed proteins, which 

 could not be differentiated, there were other chemically distinct substances 

 present in the embryo proper, which were not indicative of organismal dif- 

 ferentials. In experiments with proteoses there was a slight interaction be- 

 tween those of pea and soy bean, two nearly related substances, and in more 

 recent investigations Lewis and Wells found more definite evidence of a 

 correlation between chemical constitution and systematic relationship. 



By means of various anaphylactic methods, such as the uterus strip method 

 of Dale, the bronchospasm method and the production of shock, as well as by 

 the use of the complement fixation tests, these investigators observed that 

 the alcohol soluble proteins from certain cereal grains can be separated into a 

 wheat group and a corn group. The various proteins of the wheat group could 

 not be differentiated from one another by immunological methods, nor could 

 the members of the corn group be thus distinguished. On the other hand, 

 there were sharp distinctions and a lack of cross reactions between two 

 proteins which belonged to different groups ; analogous proteins in related 

 species behaved immunologically in the same way, but they were distinct 

 from the proteins of further removed species. These results agree with the 

 chemical analysis of these substances by Gortner and Hoffman, which showed 

 the great chemical resemblance of the analogous alcohol soluble substances 



