HOUWINK’S EXPER, CONC. THE ORIGIN OF SOME DOMESTIC ANIMALS. 147 
BATESON’s statements are for the most part confirmed by Cun- 
NINGHAM, but he has a somewhat different interpretation. He got 
two Fs's with a normal rose comb, that both had no crest. There- 
fore he identifies BATESON’s trifid element with the crest-factor. 
We don’t believe CUNNINGHAM to be right in this suppostion. 
Nowa few words about the other characters. The peculiar Sz/ky- 
' feather is recessive to the normally webbed feather. 
The white colour of the feathers is a recessive white. There are 
known at least two kinds of recessive white. BATESON supposes that 
colour can be produced only if two factors, which he calls X and 
Y are present. 
The crest-character is dominant. BATESON points out that Fo of 
a cross: crest X no crest, may contain individuals with crests far 
larger than those of the parent crested breed. This fact suggests 
that in breeds with small crests (e.g. Silky) the full development 
of the crest is kept in check by some other factor. 
We shall discuss the pigmentation of the skin more in detail 
when treating of our own results. 
3. OWN EXPERIMENTS. 
Before and beside the reciprocal crosses, the parental breeds were 
‘bred pure for several generations. The experiments with the 
Jungle-fowl started in 1912, those with the Silky in 1916. In this 
year Mr. Houwink bought 1 Silky cock and 2 hens, from a wel- 
known fancier at Nymegen — The birds were phaenotypically pure 
and tallied with the standard of the breed. — One hen died in 
1917 The resulting pair bred children in 1918 and grandchildren 
in 1919 of quite the same type, as they were themselves. 
The parent cock | 413.24 and hen | 413.1 | were quite alike apartfrom 
sex-differences. Only the cock had 4 toes, the hen 5; of course 
‘the crest of the hen was larger than that of the cock. 
The Bankiva-birds used in these experiments 201.7 4 and 201.139 
were children of the original pair 201.1 ¢ and 201.22 bought from 
Mr. J. D. HAMLYN the well-known animal-dealer in London and 
imported in 1912 directly from Java. 
This does not entirely guaranty the purity of the import, as the 
wild jungle cocks sometimes pay visits to the domestic hens in the 
