A reconstruction of Mendel's Pisum experiments and an attempt at an explanation of Mendel's way of presentation
Folia Mendeliana 6: 41-60
R. A. Fisher (1936) in reconstructing Mendel's Pisum experiments had to come to the conclusion that Mendel knew very well what to expect. A new attempt at a reconstruction of Mendel's Pisum data yielded some differences in numbers and periodical arrangement of the experiments. This fully confirms Fisher's conclusion that Mendel must have known beforehand what to expect. It is, however, improbable that the hybridizing experiments preceded the experiments on gametic ratios as Fisher thought. It is most likely that after concluding (p. 29) "that pea hybrids form germinal and pollen cells that in their composition correspond in equal numbers to all the constant forms resulting from the combination of traits united through fertilization" Mendel projected his programme of hybridizing peas differing in one or more trait pairs to demonstrate how his idea worked. From the didactic point of view, he, however, first. described his mono-, di- and trihybridizing experiments which he presumed to be more easily comprehensible to his listeners. A detailed explanation of his theory was presented later in the letter, part "On Reproductive Cells" and especially in the Concluding Remarks.