From George Robert Gray   2 April 1868

Dear Sir

I had the curiosity of enquiring from the keeper at the Gardens about the changes that take place in reference to the Scarlet Ibis.¹ He says that the bird changes its plumage on the return of the breeding season. Yet on asking the same question of the Superintendent,² he informed me, that the bird only changes once, that is from the brown plumage of the young state to the Scarlet of the mature bird; and that the only change that does take place on the return of the breeding season, is that the bill becomes black, instead of remaining of a reddish colour.³ I am now rather inclined to believe, that the Superintendent’s is likely to be the right one, as regard to the changes that do occur in the Scarlet Ibis, and, as it is in opposition to what I told you the other day, I therefore trouble you with this note⁴

I remain | Yours faithfully | G. R. Gray

C. Darwin Esq^re.