156 SEXUAL selection: BIEDS. Part II. 



latter of this colour. The result would generally be 

 the production either of a mongrel piebald lot, or more 

 probably the speedy and complete loss of the pale-blue 

 colour, for the primordial slaty tint would be trans- 

 mitted witli prepotent force. Supposing, however, that 

 some pale-blue males and slaty females were produced 

 during each successive generation, and were always 

 crossed together ; then the slaty females would have, 

 if I may use the expression, much blue blood in their 

 veins, for their fathers, grandfathers, etc., will all have 

 been blue birds. Under these circumstances it is con- 

 ceivable (though I know of no distinct facts rendering 

 it probable) that the slaty females might acquire so 

 strong a latent tendency to pale-blueness, that they 

 would not destroy this colour in their male offspring, 

 their female offspring still inheriting the slaty tint. If 

 so, the desired end of making a breed w^ith the two 

 sexes permanently different in colour might be gained. 

 The extreme importance, or ratlier necessity, of the 

 desired character in the above case, namely, pale-blue- 

 ness, being present though in a latent state in the 

 female, so that the male offspring should not be dete- 

 riorated, will be best appreciated as follows : the male 

 of Soemmerring's pheasant has a tail thirty-seven inches 

 in length, whilst that of the female is only eight inches; 

 the tail of the male common pheasant is about twenty 

 inches, and that of the female twelve inches long. Now 

 if the female Soemmerring pheasant with her short tail 

 were crossed with the male common pheasant, there 

 can be no doubt that the male hybrid offspring would 

 have a much longer tail than that of the pure offspring of 

 the common pheasant. On the other hand, if the female 

 common pheasant, with her tail nearly twice as long as 

 that of the female Soemmerring pheasant, were crossed 

 with the male of the latter, the male hybrid offspring 



