276 LOTSY AND KUIPER, A PRELIM. STATEMENT OF THE RESULTS OF MR. 
1923, in connection with a similar fact mentioned by PUNNETT in his 
Heredity in Poultry p. 36, points to the introduction of the factor for 
black into our domestic poultry through Gallus varius, to which species, 
as suggested in the text, it may also owe the barring factor. 
Taken all in all, especially also the ways in which the domesticated 
poultry has come to us, we do not think it very risky to suggest that st 
is far more probable that in the formation of our domestic poultry all 
known wild species have taken part than that it is derived from a single one. 
To this view, that hybridization is at the bottom of the great diver- 
sity of our domestic poultry, Mr. HouwInk has contributed a con- 
siderable share. 
It is far from us, to think that more than the first step has been put on 
the road which leads to a full explanation of the wayin which our domest- 
ic poultry-races have been obtained. We even acknowledge that in those 
races, as we now know them, Gallus bankiva has the lion’s share and it 
has puzzled us a good deal to find a reasonable explanation for the fact 
that — apart from the influence of the silver factor, the factor for black 
and that for barring, — so little is seen of a sonnerati- and varius-in- 
fluence in our domestic races, the only very apparent influence of varius 
being the rudimentary median wattle in the case of the Sumatra-cocks. 
This fact has puzzled the senior-author especially to such an extent 
that he has indulged in all kinds of speculations, without reaching a 
satisfactory conclusion, not so much because the fact that so little in- 
fluence of varius and sonnerati could be seen in MR. HOUWINK’s experi- 
ments, was so impressive, the progeny obtained was too small in num- 
ber for that, but on account of the apparent absence of that influence 
in domestic poultry at large. | 
Quite recently it occurred to him that , natural” selection may be at 
the bottom of this, at first so puzzling, fact. The geographical distribu- 
tion of the wild species of Gallus is very limited: Gallus lafayetti occurs 
in Ceylon only, Gallus sonnerati in British India only, while Gallus 
varius is limited to Java and to one or two small islands, which, not so 
very long ago, were one with it. The only exception is offered by Gallus 
bankiva which occurs all over the south-east of the asiatic continent 
and over a great part of the Malay Archipelago, reaching even, the 
Phillipines perhaps. 
This certainly points towards Gallus bankiva being able to withstand 
different climates much better than any of the other wild Gallus-species, 

