196 Peculiar Pigmentation of the Silhj Foivl 



F^ generation from this type of F^ $ we have already seen reason for 

 supposing that the male chicks of tlie constitution PPIi are practically 

 fully pigmented on hatching, but that the pigment becomes much 

 reduced with advancing age. Hence the expectation for the present 

 type of mating is that all the $ $ will be deeply pigmented, and that 

 the (/',/ will hatch either as deeply pigmented chicks, or as chicks 

 with some pigment only — these two classes being produced in equal 

 numbers. Table VII gives the results of the two cases in which we have 

 made this mating. While the general result is in accordance with 

 expectation the Table shows that there are two % $ from each mating 

 which are not fully pigmented. To these exceptions we shall recur 

 later (p. 200). 



TABLE VII. 



Males Females 



Reference Nature of mating Full Some None Full Some None 



1907) 



^gjjgl Pen 18, 459 Fj ? (slight pig.) x Silky j 12 13 — 28 2 — 



1907) -\ 



1908^ " ^' ^^^\ „ „ 12 18-28 2 - 



1909 „ 16, 467) 



Total 24 31 — .56 4 — 



Expectation 37-5 27-5 — 60 — — 



(7) Fi J (fully pigmented) x Silky ^. 



[Nature of mating, % ^Ppii x ^^ ^PPii.] 



Since the gametes of neither parent carry the inhibitor factor and 

 since those of one parent all contain the pigmentation factor, the 

 expected result of this mating is fully pigmented chicks only, of both 

 sexes. The mating has been made on three occasions and as Table VIII 

 shows the results are in accordance with expectation. 



We have already alluded to the deeply pigmented hens which 

 resulted from crossing the F^ </ with the Brown Leghorn $ . On our 



