224 TH3 DESCENT OF MAN. 



whether it lasts throughout life or is only transient, will, in gen- 

 eral, reappear in the offspring at the same age and last for the 

 same time. If, on the other hand, a new character appears at ma- 

 turity, or even during old age, it tends to reappear in the offspring 

 at the same advanced age. When deviations from this rule occur, 

 the transmitted characters much oftener appear before, than after 

 the corresponding age. As I have dwelt on this subject sufficiently 

 in another work,"" I will here merely give two or three instances, 

 for the sake of recalling the subject to the reader's mind. In sev- 

 eral breeds of the Fowl, the down-covered chickens, the young 

 birds in their first true plumage, and the adults differ greatly from 

 one another, as well as from their common parent-form, the Gal- 

 lus bankiva; and these characters are faithfully transmitted by 

 each breed to their 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 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." Hence in this breed variations have occurred at, and 

 been transmitted to, three distinct periods of life. The Pigeon of- 

 fers a more remarkable case, because the aboriginal parent species 

 does not undergo any change of plumage with advancing age, ex- 

 cepting 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. 



Inheritance at corresponding Seasons of the Year. — With ani- 

 mals in a state of nature, innumerable instances occur of charac- 

 ters appearing periodically at different seasons. We see this in 

 the horns of the stag, and in the fur of arctic animals which be- 

 comes thick and white during the winter. Many birds acquire 

 bright colors and other decorations during the breeding-season 

 alone. Pallas states,"" that in Siberia domestic cattle and horses 



=" '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. 



M These facts are given on the high authority of a great breeder, 

 Mr. Teebay; see 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 following paragraph, see 'Variation of Ani- 

 mals,' &c., vol. i. pp. 160, 240; vol. il. p. 77. 



"« 'Novae species Quadrupedum e Glirium ordine,' 1778, p. 7. On 

 the transmission of color by the horse, see 'Variation of Animals, 

 &c., under Domestication,' vol. i. p. 51. Also vol. ii. p. 71, for a gen- 

 oral discussion on 'Inheritance as limited by Sex.' 



