The present study concerns with the hybridization experiments attempted between the Domestic fowl (Gallus gallus var. domesticus) and the Common Pheasant (Phasianus colchicus), during the years of 1939 to 1940, and this paper includes the records of breeding, the morphology and plumage of the hybrid birds, and the results of some other oecological observations. The detailed accounts on the anatomical and cytological investigations of the hybrids will be given in other paper (Yamashina, '43).
The cross between these two forms is easily made in captivity, and no attempt was made on the artificial insemination.
In the various combinations of the parent birds, 164 hybrid eggs were obtained in total. After incubation, 46 eggs were proved to be fertilized, from which 9 unhatched embryos, 12 chicks and 9 adult birds came under our observation.
The combination of forms and their offsprings obtained are given as follows:
In the most successful combination (the Red-hackled Shamo _??_×the Korean Ring-necked Phasant _??_), 37 fertilized eggs were obtained in 100 eggs examined (37%), and in other combination, the Black Shamo _??_×the Korean Ring-necked Pheasant _??_, and the Red-hackled Shamo Bantam _??_×the Korean Ring-necked Pheasant _??_, the result showed nearly 13% for each case.
In the 46 fertilized eggs obtained in the present experiment, the sexes were determined of unhatched hybrid embryos, the birds which died after hatching and those which were killed at later stages for observations:
It is evident from the above table that among the hybrid offsprings, the sex-ratio is approximately 1 to 1. The unusual excess of males reported by previous authors in the similar cross was interpreted due to the results derived from observations on the adult stage. It seems apparent from the author's study that the mortality of female hybrids is very high during the incubation and also in the stage of chicks just hatched out.
The hatch-ability was shown to be 68% among 37 fertilized eggs incubated. Among 25 hatched chicks 9 had reached the maturity (36%).
The feather patterns of the hybrid chick produced between the Red-hackled Domestic fowl and the Pheasant were just intermediate found in the chicks of the Red Jungle-fowl and of the Pheasant. The feathers of the adult hybrid seemed to show rather primitive patterns, but the feather of the under-parts were mostly dark in colour, when the Green Pheasant was used as a parent.
In the cross between the Black Shamo _??_ and the Pheasant _??_, the colour of feathers was nearly black in both of the chick and the adult, and the gene of black colour in the Black Shamo seems to play a dominant factor in this cross.
There was found a noticable longitudinal groove running along each side of the bill of the hybrid when the Red-hackled Shamo was employed in the cross, and among seven F1 offsprings, two had well developed groove, the other two indistinct groove, and the remaining three entirely lacking.
In two F1 males of 24 months old, sex hormone injection was made, 0.5cc of Puberogen and Testosteron applied subcutaneously every other day and 6 times in all. After this injection the bare parts of the face became to appear that of young bird and very fresh, but the injection showed no marked influence upon the activity of the germ cell.