Ohai'. VIII. Sexual Selection. 229 



here merely give two or three instances, for the sake of recalling 

 the subject to the reader "s mind In several breeds of the Fowl, 

 the down-covered chickens, the young birds in their first true 

 plumage, and the adults diflfer greatly from one another, as well 

 as from their common parent-form, the Gallus hankiua ; ' and 

 these characters are faithfully transmitted by each breed to theii 

 offspring at the corresponding periods of life. For instance, the 

 chickens of spangled Hamburgs, whilst covered with down, have 

 a few dark spots on the head and rump, but are not striped 

 longitudinally, as in many other breeds ; in their first true plu- 

 mage, " they are beautifully pencilled," that is each feather is 

 transversely marked by numerous dark bars; but in their second 

 plumage the feathers all become spangled or tipped with a dark 

 round spot.'* Hence in this breed variations have occurred at, 

 and been transmitted to, three distinct periods of life. The 

 Pigeon offers a more rems^rkable case, because the aboriginal 

 parent species does not undergo any change of plumage with 

 advancing age, excepting that at maturity the breast becomes 

 more iridescent ; yet there are breeds which do not acquire their 

 characteristic colours until they have moulted two, three, or 

 four times ; and these modifications of plumage are regularly 

 transmitted. 



Inheritance at correspmiding Seasons of the Year. — With animals 

 in a state of' nature, innumerable instances occur of characters 

 appearing periodically at different seasons. We see this in the 

 horns of the stag, and in the fur of arctic animals which becomes 

 thick and white during the winter. Many birds acquire bright 

 colours and other decorations during the breeding-season alone. 

 Pallas states,'* that in Siberia domestic cattle and horses become 

 lighter-coloured during the winter ; and I have myself observed, 

 and heard of similar strongly marked changes of colour, that is, 

 from brownish cream-colour or reddish-brown to a perfect white^ 

 in several ponies in England. Although I do not know that this 

 tendency to change the colour of the coat during different seasons 



chapter but one, the provisional mals,* &c., vol, 1. pp. 160, 249 ; 



hypothesis of pangenesis, above vol. ii. p. 77. 



alluded to, is fully explained. '^ ' Novse species Quadrupednm o 

 '* These facts are given on the Glirium ordiue,' 1778, p. 7. On 

 high authority of a groat breeder, the transmission of colour by the 

 Mr. Teebay ; see Tegetmeier's ' Poul- horse, see ' Variation of Animals, 

 'sry Book,' 1868, p. 158. On the &c., under Domestication,' vol. i. p. 

 characters of chirieus of different 51. Also vol. ii. p. 71, for a gene- 

 breeds, and on the breeds of the ral discussion on ' Inheritance M 

 pigeon, alluded to in the following limited ity Sex.' 

 OariLgrapb, st^e ^ Variation of Aai- 



