578 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



majority of hormones do not possess a species-specific structure and the 

 species-specificity of their action depends on the species-specificity of the 

 substratum on which they act. Vitamins are not of a protein nature, but they 

 may combine with proteins to form enzymes. While, therefore, neither 

 vitamins nor the majority of hormones possess organismal differentials, still 

 there may be differences in the production of these substances in different 

 species, and these differences are analogous to differences in the structure of 

 organs and tissues and in the constitution of certain substances which occur 

 in these organs and which are characteristic also of these species, without a 

 relation to the phylogenetic position of the species being manifest. 



To return to the starting point of this discussion : if an immune serum is 

 produced against a conjugated protein, the immune substance in the serum 

 may combine either with the hapten or with protein acting as carrier. In order 

 to obtain a specific interaction of the antibody with the hapten alone, or 

 with the hapten or substituent groups when conjugated with a carrier 

 differing from the one which originally was a part of the antigen giving 

 rise to the antibody, it is necessary for the antigen to contain a certain 

 number of the substituent groups. If this number remains below the threshold 

 of effectiveness, it is solely the carrier which induces the antibody production ; 

 we have therefore to deal here with quantitative relations (Haurowitz, 

 Sarafran and Scherwin). In order to produce agglutinins for erythrocytes 

 to which certain sidegroups or haptens had been attached, it is necessary 

 for parts of the surface of these to be free of these attachments. Then the 

 antibody will be directed also against the erythrocytes as such and not only 

 against the hapten (Pressman, Campbell and Pauling). This condition seems 

 to be one of the factors which determines whether antibodies other than those 

 directed against the hapten will be able to cause the agglutination of the 

 erythrocytes. But also the hapten, as such, may bring about an agglutination 

 of the erythrocytes if each one of the molecules of this substance had a 

 chance to attach to itself two erythrocytes during the process of centrifuga- 

 tion. As to the manner in which a hapten can induce the production of a 

 specific antibody, the experiments of Pauling and Campbell give some indica- 

 tion; these investigators succeeded in transforming in vitro bovine gamma- 

 globulin into antibody by moderate heating, or by adding an amount of alkali 

 to the medium sufficient to start the process of denaturation; they hold that 

 the denaturing causes the globulin chain to uncoil. This gives the hapten — a 

 dye or pneumococcus polysaccharide of type III — a chance to act on the pro- 

 tein, which thus assumes a configuration most stable under these conditions, 

 one complementary to the configuration of the hapten. A subsequent lowering 

 of the temperature of the solution or a restoration of the neutral state effects 

 a renaturation process in the protein, which then represents a specific antibody. 

 On the other hand according to Erickson and Neurath regeneration of de- 

 natured antibody protein may take place even without the presence of the 

 specific antigen and they suggest that the difference between normal globulin 

 and antibody globulin may be due to differences in the aminoacid composition 

 of these proteins. 



