5 ON EXrERIMKNTAL PHJBASAXT-BKBEDING. 



" In Elliot's ' Phasianidse ' is a coloured plate of a pair of 

 Thaumalea ohscura with their young, which were considered by 

 him and some other ornithologists as a variety of picta ; according 

 to this plate the birds apparently bred true. 



"In my pheasantry in 1907, three Amherst hens were mated 

 with a Golden cock and produced a number of young called F, in 

 the pedigree. In 1909 two pairs of these F, birds were mated, 

 and from these two pens 20 F^ chicks were hatched. Amongst 

 them were three chicks of a deep chocolate-brown, in startling 

 contrast to the others, which were cream-colour with a bronzing of 

 russet on the back and throat. The down of these ohscura chicks 

 Avas of a uniform dark brown to the skin, and each eye was 

 rimmed with a, finely pencilled cream line, which was connected 

 by another cream line across the top of the bill, giving the quaint 

 appearance of a pair of specta,cles ; there was also a cream patch 

 on the throat, varying in size in each individual, sometimes being 

 a mere spot. The legs were a dull olive-brown. These brown 

 chicks were produced from both pens, and were of both sexes, 

 but unfortiuiately only one of the three (a cock) was reared. 

 Thamnalea birds attain adult plumage only in the second }'ear, so 

 it was not till July this year that my surmise that ohscura 

 had been produced was confirmed. The cock has the same barred 

 tail (pattern Amherst, coloration C4olden), and the same dai-k 

 brown on head and throat and neck, as the bird depicted on Elliot's 

 plate, but his breast is a duskier red and the crest and mantle 

 paler. When a chick, his coloration was similar to the young 

 shown on Elliot's plate, only the brown was a deeper, richer shade. 

 This F^ cock was mated in the spring of 1910 with two F^ hens, 

 his sisters. The darkest hens were picked out, with Golden eye- 

 skin (yellow with red round the rim) ; Amhei'st hens are lighter 

 and greyer in plumage than the Golden, and the eye-skin is a 

 greenish blue. From this mating eight birds were hatched, four 

 cream-coloui-ed and four dark brown chicks ; these last had pre- 

 cisely the same coloration as that of the father. The numbers 

 tally with those to be expected according to Mendel's laAv. I 

 hope to obtain more evidence next season from the same birds, 

 and to have better luck, for all these eight chicks lived only a few 

 days. As I intend to breed again from him, I caimot show you 

 the skin of the a,dult ohscura cock, biit only some feathers plucked 

 from his breast and back, and the skins of his two brothers and 

 of two of his sisters. An examination of these breast-feathers 

 plucked from ohscura and of some of the breast-feathers of the 

 cock marked '■ s,eYa\- ohscura' will show the reason of the so-called 

 ' duskiness' of hue ; each feather has a bar of metallic green on 

 the inner half, while the outer end of it is led. You will observe 

 in the Golden cock that the breast-feather is red throughout. 



" Apparently, then, Thaumalea ohscura is a hybrid recessive 

 mutation, breeding true, as shewn in Elliot's plate and also in my 

 experiment this year, according to Mendel's law. I ha^e used 

 the word ' mutation,' but these birds may possibly be a I'eversion 

 to the ancestral parent form of both '' species" of Thamiialea. 



