 In Johannsen’s experiments, the plants in any line showed variation in a given trait under differing conditions, but selection among the plants for that trait did not result in improvement from one generation to the next. Whatever the nature of the germ cells that seeds from a line shared, and in whatever ways it “reacted” during the plant’s development thus “interfering with the totality of all incident factors, may it be external or internal” (1911: 133), seeds of the next generation did not result in plants that matched their parent any more than plants from any other seed from the same line (a theory summarized in  Figure 1).  Plants from the inbred line were instances of a genotype; variation in the traits grown from the seeds was, borrowing from Richard Woltereck, the norm of reaction (Reaktionsnorm) of that genotype; a plant’s relative position in the norm of reaction was not transmitted to its offspring; and (with the emphasis Johannsen’s) “selection is not able to shift the nature of genotypes” (1911: 137). Because the nature or constituents of a genotype were stable, the “genotype-conception” of heredity was “ahistoric” (1911: 139). (Note: Johannsen did not adopt Weismann’s term germplasm to denote the material basis for animal development sequestered from the somatoplasm early each generation [Churchill 1974: 19]. Yet, whatever the material basis of development was for plant genotypes, it was similarly shielded from most of the interactions that occur during the organism’s lifetime within the organism and with the environment.)