90 MR. W. BATESOX ON COLOUR-HEREDITY [May 26, 



The most striking fact about the F^ heterozygotes (not men- 

 tioned in Darbishu'e'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, jxist 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 cer- 

 tainly suggests that the coniphieness 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 h is 

 the same colour f as the pale fawn of the original waltzers, it is 

 curious to find that in F, there were black-eyed (therefore pre- 

 sumably heterozygous) "fawn-yellows," when the colour grey 

 would have been the natural expectation. This phenomenon 

 majr be compared with that seen in von Guaita's work, where 

 original black-and-white x albino gave greys ; but in Fg 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"i _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 F^ (presumably from 

 ■wild coloured F^) as increased to 66, and though the individuals 

 are not classified according to colours, the information is given 

 that there were — 



Albinos Coloured Coloured (? all) 



pk-eyed. pk-eyed. dk-eyed, 



13 17 36 



the expecta- 1 . „ 5. ^ ^ _ 



tionbeing|l«-'5 16-5 83 



* Darbishire's being, however, mostly pied, while von Guaita's were selfs. 



t Until qualitative details of these colorations are published, their exact nature 

 can only be surmised. 



X [From a specimen exhibited by Mr, Darbishire, I think this colour is probably 

 one of the dilutions of 6 rotpii pigment. It appeared to be a paler shade of the 



silver of fanciers.] 



