HOUWINK’S EXPER. CONC. THE ORIGIN OF SOME DOMESTIC ANIMALS. 157 
2 X Bankiva ¢ led him to the same conclusions as ours do us. He 
writes: „There is no need for such an assumption (the presence in 
the brown Leghorn of a sexlinked factor which can suppress or 
mask the development of the pigmentation) in the case of the 
Bankiva cock, but it must be noted that I have no experience of 
the opposite cross, Bankiva hen with Silky cock.” 
It might be worth while quoting CUNNINGHAMS description of 
his anatomical researches on this subject. He writes: „I was led to 
consider the possibility of slight degrees of body pigmentation 
by. the description of such degrees given by BATESON and PUNNETT 
in their recent paper in the Journal of Genetics vol. I no. 3. Accor- 
dingly I killed No. 10 of the Fo’s, which had the white colour 
and Silky character in its plumage, and apparently normal colour 
in comb and skin, that is to say the comb etc. was blood red, and 
the skin, so far as could be seen between the feathers unpigmented. 
Before the bird was plucked, however ‚I noticed a ring of dark 
colour on the lips of the cloacaly aperture. On further examination I 
found considerable pigmentation of the subcutaneous tissue of the 
abdomen behind the sternum, which was the cause of the darkening, 
above mentioned, of the lips of the cloaca. There was subcutaneous 
pigment on the tarsal joint and all down the tarso-metatarsus but 
none on the knee-joint. It occurred also on the elbow-joint of the 
wing and on the wrist-joint, but not at the shoulder-joint. 
In all cases the pigment was visible externally as a darkening 
of the skin and under the microscope as a reticulum of pigmentcells 
in the connective tissue. On the peritoneum the pigmentation was 
slight but distinct, not only on the outer wall but also over the 
intestines, for example on the gizzard; the surface of the testes 
was also black over the anterior three fourth of the organ, while 
the porterior fourth was white”. : 
Further CUNNINGHAM discribes a thorough examination of a normal 
specimen of Gallus bankiva as follows: „I found a little pigment 
in the subcutaneous tissue about the ankle joint posteriorly, but 
none in the periosteum; this pigment was merely a slight extension 
_of the pigment on the inner surface of the skin, which extended 
down the tarsometatarsus as in the F2 recessive. 
In both cases the shanks appeared externally olive-green. In the 
Bankiva there was no pigmentation anywhere else, either in the 
