Derselbe zerfällt daher in eben so viele einzelne Experimente, als constant differirende Merkmale an den Versuchspflanzen vorkommen.
The experiment therefore breaks up into as many individual trials as there are constantly differing traits in the experimental plants.
The experiment = Derselbe The reference of this demonstrative pronoun is unambiguous, as Versuch is the only male noun in the preceding sentence. Sherwood have “study”, probably to convey the sense in which Mendel here distinguishes between a whole series of systematically related experiments, and its individual components.
breaks up = zerfällt Bateson has “resolves itself”. We follow Sherwood’s translation which is more literal. Mendel’s choice of words leaves open the possibility that he in fact carried out polyhybrid crosses, and then analyzed the results in retrospect with regard to mono- di- and polyhybrid inheritance; see Federico di Trocchio, “Mendel’s experiments: a reinterpretation”, Journal of the History of Biology 24 (1991): 485–519.
trial = Versuch See p. 3, s. 6.
constantly differing = constant differirende Bateson has “constantly differentiating”; see p. 5, s. 5.