94 INHERITANCE IN POUI<TRY. 



shafting on the contour feathers, although the white shafting is much 

 broadened. When the barred male and broad-shafted females of this first 

 hybrid generation were crossed the pure plumage of the Tosa fowl tends to 

 reappear. The males have contour feathers without white and with much 

 red ; the females have the shafted feather without any red. "With maleness 

 or femaleness go the proper secondary attributes. 



What is true of the Tosa fowl is true generally, and there is much oppor- 

 tunity to test this matter in poultry, for sexual dimorphism is widespread. 

 In all "dark" or "partridge," silvered, and golden races as found in 

 Brahmas, Cochins, Wyandottes, Dorkings, Hamburghs, Games, and Oriental 

 fowl, the plumage of the two sexes is conspicuously different ; and to pro- 

 duce sexual dimorphism in a race that is without it the use of one male 

 bird of a dimorphic race may suffice. Again, in the male, comb and wattles 

 are generally larger than in the female. The rose comb of the male becomes 

 often a modified pea comb in the female. The simple comb of the Minorca, 

 Spanish, and Dorking fowl is erect in the male, drooping to one side (equally 

 to the right and left side) in the female. The form of the hackle and saddle 

 feathers constitutes one of the most constant differences between the two 

 sexes. These are long, narrow, and pointed in the male ; short, broad, and 

 rounded in the female. The tail feathers differ similarly. The sickle feathers 

 and those of the middle row especially continue to grow in the male long after 

 their growth has ceased in the female. Similarly the crest feathers of Polish 

 and Houdans grow longer in the male than in the female, but on account of 

 t heir greater breadth i n the female her crest appears larger and fuller. L,astly , 

 the greater development of the spurs in the male over six to eight months 

 old is a well-marked dimorphic character. Of these characters I have paid 

 most attention to plumage and skin color, and will take up in review the 

 results gained in crossing dimorphic species. 



Black Minorca and Dark Brahma. — The male Dark Brahma has white- 

 laced hackles and black, white, and red wing bars. In the female the lacing 

 on the hackles is less conspicuous, and there are no wing bars or bows. 

 Red is wholly absent. All hybrids are prevailingly black. All males, how- 

 ever, show a more or less prominent wing-bar formed of black, straw, and 

 red colored feathers. No females show any trace of a wing bar unless it be a 

 slight iridescence in the wing coverts. 



White Leghorn and Dark Brahma. — The male hybrids are typically white, 

 with some red on wing coverts. Apart from some black individuals, the 

 female hybrids are either white, with some buff on wing, or else they resem- 

 ble the female Dark Brahma, having the penciling modified into mossiness. 

 There is no well-defined wing-bar, but the middle wing is suffused with red. 



White Leghorn and Houdan. — Neither of these races exhibits a marked 

 dimorphism in plumage color. Nevertheless, the coloration of the hybrids 

 is dissimilar in the two sexes, the males being of a much purer white than 



