C «AP. VIII. 
SEXUAL SELECTION. 
281 
to reappear in tire offspring at the same advanced age. 
When deviations from this rule occur, the transmitted 
characters much oftener appear before than after the 
corresponding a ire. As I have discussed this subject 
at sufficient length in another work, 11 ’ I will here merely 
give two or three instances, for the sake ot recalling the 
subject to the reader’s mind. In several breeds of the 
Fowl, the chickens whilst covered with down, the young 
birds in their first true plumage and in their adult plum- 
age, differ greatly from each other, as well as from their 
common parent-form, the Gallus lanldm ; and these 
characters are faithfully transmitted by each breed to 
their offspring at the corresponding period of life. For 
instance, the chickens of spangled Hamburghs, whilst 
covered with down, have a few dark spots oil the head 
and rump, but are not longitudinally striped, as in 
niany 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 
0r tipped with a dark round spot . 20 Hence in this 
breed variations have occurred and have been trans- 
mitted at three distinct periods of life. The Pigeon offers 
a more remarkable case, because the aboriginal parent- 
species does not undergo with advancing age any change 
°f plumage, excepting that at maturity the breast 
becomes more iridescent; yet there are breeds which 
do not acquire their characteristic colouis until thej 
19 ‘The Variation of Animals and Plants under Domestication’ voL 
li - 1868, p. 75. In the la>t chapter but one, the provisional hypothesis 
pangenesis, above alluded to, is fully explained. 
„ :u These facts are given on the high authority of a great breeder, 
® r - Teebay, in Tegetmeier’s ‘Poultry Boole,’ 1868, p. 158. On the 
characters of chickens of different breeds, and on the breeds of the 
h'geon, alluded to in the above paragraph, see ‘ Variation of Animals," 
& c., vol. i. p. ICO, 249 ; vol. ii. p. 77. 
