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Show 90 MR. W. BATESON ON COLOUR-HEREDITY [May 26, The most striking fact about the F, heterozygotes (not mentioned in Darbishire's first paper) is that they all had dark eyes, though both parents had pink eyes. The albino showed itself a recessive as usual. Moreover, just as in von Guaita's case, the colour of the waltzers did not behave as a simple dominant, but formed a specific and reversionary heterozygote. It is especially interesting that this heterozygote should have been so nearly the same *, though Darbishire's original coloured form was " fawn "- and-white, while von Guaita's was black-and-white. This certainly suggests that the completeness of the reversion may have been due to the meeting of some other dissimilarities than those indicated simply by colour and albinism {cf. Steer's case of chocolates, p. 85). Other facts point in the same direction. Moreover, if the " fawn-yellow" of Darbishire's class b is the same colour t as the pale fawn of the original waltzers, it is curious to find that in F2 there were black-eyed (therefore presumably heterozygous) " fawn-yellows," when the colour grey would have been the natural expectation. This phenomenon may be compared with that seen in von Guaita's work, where original black-and-white X albino gave greys; but in F2 black-and- white may be a simple dominant over albino. (Compare also Parsons' evidence as to chocolate (= brown) with Steer's experience.) The result of mating the wild-coloured F, together, as far as the detailed tabulation extended, was : Albino 9 all pink-eyed. Yellow 4 3 pink-eyed. Fawn-yellow 6 3 pink-eyed. Pale grey 9 Dark grey 1 Black 5 "Lilac"} _3 1 pink-eyed 37 In all, therefore, 16 were pink-eyed and 21 dark-eyed, when equality is expected. A postscript gives the number raised in F2 (presumably from wild coloured FA as increased to 66, and though the individuals are not classified according to colours, the information is given that there were- Coloured (? all) dk-eyed. 36 33 * Darbishire's being, however, mostly pied, while von Guaita's were selfs. f Until qualitative details of these colorations are published, their exact nature can only be surmised. t [From a specimen exhibited by M r . Darbishire, I think this colour is probably one of the dilutions of brown pigment. It appeared to be a paler shade of the " silver " of fanciers.] Albinos pk-eyed. 13 the expecta- ] , „ _ ,. K . } 16-5 tion bemg J Coloured pk-eyed. 17 16-5 |
