on ancestral characters in nestlings.



235



■the character of plumage which they still retain is of far greater

antiquity than that of birds of more specialised and striking

appearance. Of course, in the first case, the male has been

differentiated by sexual selection, and in the second the colouring

has been retained for protective purposes; whereas in the Pigeons

referred to the female has inherited her colouring through her male

ancestry.


Now, if we admit this, would not the result of hybridising

(birds in which the sexes resembled each other with those in which



A spot-breasted nestling Sedge-Warbler.


they differed greatly, tend to produce females with partly developed

male characteristics? If so (and it ought to in my opinion), would

it not throw light upon the process by which the female colouring

was modified so as to resemble that of the male? It would be an

interesting experiment.


As recorded in ‘ British Birds with their Nests and Eggs,’

I caught a bird in my garden which I concluded was a Thrush and

Blackbird hybrid, the upper parts being deep smoky brown, the

chin and throat white streaked with dull black; the breast in certain

lights showing traces of the true Song-Thrush spotting; the bill,

which was formed like that of a cock Blackbird, was deep orange

with the basal half of the culmen black; the feet were yellowish

horn-brown.



