My dear Sir

I do not know that the sexes in Annelids (proper) differ in colour— It is so seldom that I see them except in spirits, when generally their colour is pretty well discharged— I should say however that as far as I know they do not— In the Entozoa, the colour does often shew a difference— I have now before me specimens of a species of Sclerostoma¹—the females of which are abundant—the males very few in number— The former are red or reddish, the latter (taken at the same time from the same animal) is quite white—²

Believe me | Your’s very truly | W Baird