446 The Descent of Man. Part II, 



of the latter, the male hybrid offspring would have a much 

 shower tail than that of the pure offspring of Scemmerring's 

 pheasant. 3 



Our fancier, in order to make his new breed with the males 

 of a pale-blue tint, and the females unchanged, would have to 

 continue selecting the males during many generations; and 

 each stage of paleness would have to be fixed in the males, 

 and rendered latent in the females. The task would be tn 

 extremely difficult one, and has never been tried, but might 

 possibly be successfully carried out. The chief obstacle would 

 be the early and complete loss of the pale-blue tint, from the 

 necessity of reiterated crosses with the slaty female, the latter 

 not having at first any latent tendency to produce pale-bluo 

 offspring. 



On the other hand, if one or two males were to vary ever so 

 slightly in paleness, and the variations were from the first 

 limited in their transmission to the male sex, the task of making 

 a new breed of the desired kind would be easy, for such males 

 would simply have to be selected and matched with ordinary 

 females. An analogous case has actually occurred, for there are 

 breeds of the pigeon in Belgium 4 in which the males alone are 

 marked with black striae. So again Mr. Tegetmeier has recently 

 shewn 5 that dragons not rarely produce silver-coloured birds, 

 which are almost always hens; and he himself has bred ten 

 such females. It is on the other hand a very unusual event 

 when a silver male is produced ; so that nothing would be 

 easier, if desired, than to make a breed of dragons with blue 

 males and silver females. This tendency is indeed so strong 

 that when Mr. Tegetmeier at last got a silver male and matched 

 him with one of the silver females, he expected to get a breed 

 with both sexes thus coloured ; he was however disappointed, 

 for the young male reverted to the blue colour of his grand- 

 father, the young female alone being silver. No doubt with 

 patience this tendency to reversion in the males, reared from an 

 occasional silver male matched with a silver hen, might be 

 eliminated, and then both sexes would be coloured alike ; and 

 this very process has been followed with success by Mr. 

 Esquilant in the case of silver turbits. 



With fowls, variations of colour, limited in their transmis- 

 sion to the male sex, habitually occur. When this form of 



3 Temminck says that the tail of For the common pheasant, see 



the female Phasianus Sccmmerringii IVEacgillivray, ' Hist. Brit. Birds/ 



is only six inches long, 'Planches vol. i. pp. 118-121. 



coloriees/ vol. v. 1838, pp. 487 and * Dr. Chapuis, ' Le Pigeon Voya 



488: the measurements above given gear Beige/ 1865. p. 87. 



wei« noa;le for me by Mr. Scla^r. 5 The 'Field/ Sept. 1872. 



