11 
“Тһе abnormality appears at the age of two months or a little more, disappearing at the еросһ 
of the first moult by the blackening of the light portion of the feathers. The white marking is 
less seldom seen in adult specimens and then it lasts a long time, and 1 have observed it for 
several consecutive years. 
* Under microscopical examination the shaft of some of the tail-feathers of birds affected by this 
abnormality seemed as if the birds were out of health. "Taking this fact into account, and that 
such birds are weaker than ordinary individuals, we must conclude that the abnormal plumage is 
really the effect of a retarded and irregular moult. Their system being weakened, they would fall 
into an unhealthy condition, and it is certainly very difficult to keep them alive. Albinism is 
associated with atavic characters in the disposition of the young birds. "The position occupied by the 
whitish band on a regular portion of the plumage seems to me to be explained by atavic phenomena, 
and one can thus understand the reason of an interesting process. Regarding the appearance of the 
zones, it seems that the one on the tail comes first, if not at the same time as that on the wing. 
Тһе band seems to disappear without any influence of moulting, and even sometimes without any 
partial abrasion of the feathers. For the various positions of the band on the tail what reason can 
we give? The zone which from its atavic character resembles that of other species may be formed 
in that part which by the weakness of the bird, or from some other cause, is more liable to change: 
sometimes the zone is patterned in the centre of the feathers, being margined above and below by a 
darker colour, as in the Peewit and Golden Eagle. Sometimes, however, the zone occupies a 
different area by its extension and situation, and it is very probable that in the progression of the 
darkening of the tail the differences which we have noted with regard to the extension and the 
position of the zone should be attributed to the difference in the age of the birds, as I have observed 
with regard to the colours of the latter” У. 
The descriptions are taken from the series of birds in the British Museum, and the specimens 
figured are a pair of adult birds from Heligoland in the Seebohm Collection, the young bird being 
from Sheffield in the same Collection. [Е. B. S.] 
* Of. Arrigoni degli Oddi (E.), “ Sulla Colorazione a fascie in alcuni individui giovani della Merula nigra,” Atti R. Ассай. 
Scienze di Padova, vol. iii. disp. iv. (1887), and **Studi sugli Uccelli uropterofasciati,” Atti Soc. Ven.-Tr. Sc. Nat. vol. xi. 
fasc. ii. (1890) con tav. 
са 
