538 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



stronger concentrations. Likewise sheep and goat hemoglobins react with 

 the immune sera against hemoglobin from either of these two species and 

 immune serum for human hemoglobin reacts also with monkey (Macacus 

 rhesus) hemoglobin. Immune serum directed against chicken hemoglobin may 

 react with hemoglobin from turkey, duck and pigeon, although not with 

 hemoglobin from goose. If immune serum against cattle hemoglobin is 

 exhausted with cattle erythrocytes, all the antibodies against any kind of 

 hemoglobin are removed, but if such cattle immune serum is exhausted with 

 sheep or human corpuscles, only the antibodies against sheep and human 

 hemoglobin, respectively, are removed. In this instance we have to deal with 

 a phenomenon similar to that observed in the case of fibrinogen. 



Heidelberger and Landsteiner demonstrated the specificity also of crystal- 

 line hemoglobin and were able to show that the precipitate which forms, 

 when hemoglobin and its immune serum are mixed, is due to hemoglobin 

 as such acting as an antigen and not to an adhering impurity. They further- 

 more found the specificity of hemoglobins derived from different species to 

 be very great ; thus horse hemoglobin immune serum reacts much more 

 strongly with horse hemoglobin than with that of the donkey. In addition, 

 the reaction was found to be substance-specific, the immune serum against 

 horse hemoglobin reacting not at all or only very weakly with serum albumin 

 from horse. However, according to Higashi, immune serum against chicken 

 hemoglobin gives a reaction of equal or nearly equal intensity with hemo- 

 globin of pigeon or sparrow; this, then, would indicate a restriction of the 

 species-specificity of hemoglobin. Hemoglobin has, therefore, a marked organ- 

 specificity and a definite although somewhat less marked organismal-specificity, 

 comparable to that of serum proteins. 



According to Ottensooser and Strauss, globin, which can be split off from 

 hemoglobin, also has a similar organ- and species-specificity. Immune sera 

 against horse globin and against horse serum do not give cross-reactions if 

 the complement fixation is used as a test, but if precipitation is the test method, 

 immune serum against globin from horse reacts also with horse serum as a 

 whole, but not with albumin from horse serum, while immune serum against 

 horse serum does not give a precipitate with globin. By preparing amino- 

 and nitroglobin further structural specificities are produced. Anti-globin sera 

 reacted with anti-nitro- and anti-aminoglobin sera, but the reciprocal reac- 

 tions did not take place ; anti-amino- and anti-nitroglobin sera reacted only 

 with their respective antigens, but not with globin. 



In these experiments the relationships of hemoglobins of various species 

 were tested by means of immune sera and a substance- (tissue) specificity, 

 as well as an organismal-specificity, was found ; the antigens, within a certain 

 range of accuracy, behaved in accordance with the relationships of the various 

 species. Reichert and Brown had previously observed that also the structure 

 of the hemoglobin crystals corresponded to the phylogenetic relationships of 

 the species from which they were derived. These criteria did not, however, 

 suffice for the differentiation of horse, donkey and mule hemoglobin. How- 



