[36] [This statement of Mendel’s in the light of present knowledge is open to some misconception. Though his work makes it evident that such varieties may exist, it is very unlikely that Mendel could have had seven pairs of varieties such that the members of each pair differed from each other in only one considerable character (wesentliches Merkmal). The point is probably of little theoretical or practical consequence, but a rather heavy stress is thrown on “wesentlich.”]
[37] [Note that Mendel does not state the cotyledon-colour of the first crosses in this case; for as the coats were thick, it could not have been seen without opening or peeling the seeds.]
[38] [“False hybridism” was of course unknown to Mendel.]
[39] [This and the preceding paragraph contain the essence of the Mendelian principles of heredity.]
[40] [To prove, namely, that both were similarly differentiated, and not one or other only.]
[41] [Whether segregation by such units is more than purely fortuitous could probably be determined by seriation.]
[42] [In the original the sign of equality (=) is here represented by +, evidently a misprint.]
[43] [This is the only passage where Mendel can be construed as asserting universal dominance for Pisum; and even here, having regard to the rest of the paper, it is clearly unfair to represent him as predicating more than he had seen in his own experiments. Moreover in flower and seed-coat colour (which is here meant), using his characters dominance must be almost universal, if not quite.]
[44] [It appears to me clear that this expression is incorrectly given, and the argument regarding compound characters is consequently not legitimately developed. The original compound character should be represented as A1A2A3 . . . which when fertilised by a1 gives A1A2A3 . . . a as the hybrid of the first generation. Mendel practically tells us these were all alike, and there is nothing to suggest that they were diverse. When on self-fertilisation, they break up, they will produce the gametes he specifies; but they may also produce A1A1 and A2A2, A1A2a, &c., thereby introducing terms of a nature different from any indicated by him. That this point is one of the highest significance, both practical and theoretical, is evident at once.]
[45] [It seems very doubtful if the zygotes are correctly represented by the terms A1aA2a, A2aa, A1aa; for in the hybrids A1a, &c. the allelomorphs A1 and a, &c. should by hypothesis be separated in the gametes.]