16 THE BIOLOGICAL BASIS OF INDIVIDUALITY 



chemical characteristics, which differ from those possessed by every other 

 individual of the same species. 



Two possible schematic representations of the chemical constitutions of two 

 different individuals may be considered: (1) Individual A: T la — T 2a — T 3a — 

 T 4a . . . . Individual B: T lb — T 2b — T 3b — T 4b . (2) Individual A: T la — T 2b — 

 T 3c — T 4 d. . . • Individual B: T lm — T 2n — T 3o — T 4p . T x , T 2 , T 3 , T 4 represent 

 organ and tissue differentials, such as those of liver, kidney, thyroid, cartilage 

 and ear. Provisionally they may be assumed to be identical in two individuals 

 belonging to the same species and variety, although this assumption may not be 

 entirely correct, a, b, c, d represent the individuality differentials which are 

 different in the corresponding organs and tissues of two individuals. In the 

 first mode of representation all the organs and tissues of individual A have 

 the factor a in common, while in individual B all organs and tissues have the 

 factor b in common ; a is the individuality differential of individual A ; b is 

 the individuality differential of individual B. In the second mode of represen- 

 tation each organ and tissue of individual A has its own specific factor; one 

 has a, the other b, a third one c, and so on, while the organs and tissues of 

 individual B also are distinguished from one another by specific factors, m, n, 

 o and p . . . but the factors in individual A differ from those of individual B ; 

 the factors a, b, c and d ... in their totality represent the individuality differ- 

 ential of individual A, while the factors m, n, o and p ... in their totality 

 represent the individuality differential of individual B. According to the 

 second mode of representation each organ and tissue differential of an in- 

 dividual possesses its own index of individuality, and every organ and tissue 

 would possess a secondary or accessory individuality differential. According 

 to the first mode of representation the individuality differential attached to 

 each organ and tissue of individual A would be the same, and those attached 

 to the individuality differentials of the organs and tissues of individual B 

 would be identical ; these individuality differentials would correspond to the 

 primary individuality differentials. 



It will be necessary to decide between these two possibilities. If we adopt 

 the first mode of representation, the various tissue constituents, lymphocytes, 

 fibroblasts, blood vessels, polymorphonuclear leucocytes, would react against 

 all the constituent parts of individual A in about the same manner, because 

 these parts have the same factor in common. The same applies to constituent 

 parts of individual B. But if we adopt the second interpretation, each of these 

 tissue constituents would have to remember — to speak metaphorically — an 

 endless number of tissue and organ factors which are attached to the con- 

 stituents of its own body and would have to distinguish these from a multi- 

 plicity of tissue and organ factors possessed by a different individual. Corres- 

 pondingly, the blood serum of individual A would be favorable to all the con- 

 stituent parts of individual A, and would be less favorable to all the consti- 

 tuent parts of individual B, because the factor a, or a factor correlated with a, 

 in the blood serum of individual A would be adapted to the tissue and organ 

 factor a of individual A, and would be less favorable to factor b of individual 

 B. The second concept would only with great difficulty explain these specific 



