272 THE PRINCIPLES OF [Part II, 



from this rule occur, the transmitted characters much of- 

 tener appear before than after the corresponding age. As 

 I have discussed this subject at sufficient length in another 

 work, 19 I will 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 chickens while covered 

 with down, in their first true plumage, and in their adult 

 plumage, differ greatly from each other, as .well as from 

 their common parent-form, the Gallus bankiva / and these 

 characters are faithfully transmitted by each breed to their 

 offspring at the corresponding period of life. For instance, 

 the chickens of spangled Hamburgs, while covered with 

 down, have a few dark spots on the head and rump, but 

 are not longitudinally striped, as in many other breeds ; in 

 their first true plumage, " 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. 20 

 Hence in this breed variations have occurred and have 

 been transmitted at three distinct periods of life. The 

 Pigeon offers a more remarkable case, because the abori- 

 ginal parent-species does not undergo with advancing age 

 any change of plumage, excepting that at maturity the 

 breast becomes more iridescent ; yet there are breeds which 

 do not acquire their characteristic colors until they have 

 moulted two, three, or four times ; and these modifications 

 of plumage are regularly transmitted. 



19 ' The Variation of Animals and Plants under Domestication,' vol. ii. 

 1868, p. 75. In the last chapter but one, the provisional hypothesis of 

 pangenesis, above alluded to, is fully explained. 



20 These facts are given on the high authority of a great breeder, Mr. 

 Tecbay, in Tegetmeier's 'Poultry Book,' 1868, p. 158. On the characters 

 of chickens of different breeds, and on the breeds of the pigeon, alluded 

 to in the above paragraph, see ' Variation of Animals,' etc. vol. i. pp. 160, 

 249 ; vol ii. p. 77. 



