Chap. XV. SEXUALLY-LIMITED INHERITANCE. 157 



would have a much shorter tail than that of the pure 

 offspring of Soemmerring's pheasant.^ 



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

 males of a decided pale-blue tint, and the females un- 

 changed, 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 an extremely 

 difficult one, and has never been tried, but might pos- 

 sibly succeed. The chief obstacle would be the early 

 and complete loss of the pale-blue tint, from the neces- 

 sity of reiterated crosses with the slaty female, the 

 latter not having at first any latent tendency to produce 

 pale-blue 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 ^ in which the males 

 alone are marked with black striae. In the case of the 

 fowl, variations of colour limited in their transmission to 

 the male sex habitually occur. Even when this form of 

 inheritance prevails, it might well happen that some 

 of the successive steps in the process of variation might 

 be transferred to the female, who would then come to 

 resemble in a slight degree the rnale, as occurs in some 

 breeds of the fowl. Or again, the greater number, but 



3 Temminck says that the tail of the female Phasianus Soemmerringii 

 is only six inches long, ' Planches coloriees,' vol. v. 1838, p. 487 and 

 488 : the measurements above given were made for me by Mr. Sclater. 

 For the common pheasant, see Macgillivray, 'Hist. Brit. Birda,' vol. i. 

 p. 118-121. 



* Dr. Chapuis, 'Le Pigeon Voyageur Beige,' 18G5, p. 87. 



