Moreover, feeling perfectly clear, from the fact of the absence of intermediates, that the case must be one of simple dominance in spite of first appearances, I suggest the following account with every confidence that it is the true one. There have been several “_Imperials_,” though _Dwarf Imperial_, in a form which I can feel sure is Seton’s form, I have not succeeded in seeing; but from Vilmorin’s description that the peas when ripe are “_franchement verts_” I feel no doubt it was a green pea _with a green skin_. If it had had a transparent skin this description would be inapplicable. Having then a green skin, which may be assumed with every probability of truth, the seeds, even though the cotyledons were yellow, might, especially if examined fresh, be indistinguishable from those of the maternal type. Next from the fact of the mixture in the second generation we learn that the _semi-transparent seed-coat of the paternal form was dominant_ as a plant-character, and indeed the coloured plate makes this fairly evident. It will be understood that this explanation is as yet suggestive, but from the facts of the second generation, any supposition that there was real irregularity in dominance in this case is out of the question[87]. [87] Since the above passage was written I find the “_Imperials_” described in “Report of Chiswick Trials,” _Proc. R. Hort. Soc._ 1860, I. p. 340, as “skin thick”; and on p. 360 “skin thick, blue”; which finally disposes of this “exception.” (3) _Tschermak’s exceptions._ These are a much more acceptable lot than those we have been considering. Tschermak was thoroughly alive to the seed-coat question and consequently any exception stated as an unqualified fact on his authority must be accepted. The nature of these cases we shall see. Among the many varieties he used, some being _not_ monomorphic, it would have been surprising if he had not found true irregularities in dominance. (3 _a_) _Buchsbaum case._ This variety, growing in the open, gave once a pod in which _every seed but one was green_. In stating this case Professor Weldon refers to _Buchsbaum_ as “a yellow-seeded variety.” Tschermak[88], however, describes it as having “_gelbes, öfters gelblich-grünes Speichergewebe_” (cotyledons); and again says the cotyledon-colour is “_allerdings gerade bei Buchsbaum zur Spontanvariation nach gelb-grün neigend!_” The (!) is Tschermak’s. Therefore Professor Weldon can hardly claim _Buchsbaum_ as “yellow-seeded” without qualification. [88] (36), p. 502 and (37), p. 663. _Buchsbaum_ in fact is in all probability a blend-form and certainly not a true, stable yellow. One of the green seeds mentioned above grew and gave 15 _yellows_ and three _greens_, and the result showed pretty clearly, as Tschermak says, that there had been an accidental cross with a tall green.