TO J.L.A.DE QUATREFAGES.

Down, April 25 [1861].
I received this morning your "Unite de l'Espece Humaine" [published in 1861], and most sincerely do I thank you for this your very kind present.

I had heard of and been recommended to read your articles, but, not knowing that they were separately published, did not know how to get them.

So your present is most acceptable, and I am very anxious to see your views on the whole subject of species and variation; and I am certain to derive much benefit from your work.

In cutting the pages I observe that you have most kindly mentioned my work several times.