To Frederick Smith   29 April [1859]¹

My dear Sir

Would you be so kind as to tell me whether you ever saw, the Slaves in the nests of F. sanguinea, go out in search of food or materials for their nest— I never did; but then there were but few slaves, when I watched for long hours.—²

Huber asserts that they do, & more especially in the morning.³ I think (?) you told me that you had not seen them go out & that you considered them household slaves.⁴

Have you watched the colonies of F. sanguinea pretty often, & if you have not seen the slaves go foraging, will you permit me to quote you in support of what I have never seen, after many hours on many days observation.

The suspicion crosses me that Huber’s F. sanguinea (Pl. 2 fig 5, 6 & 7) may be a closely allied, but different, species from ours: I see you do not give this reference to Huber.—⁵

Pray forgive my troubling you, & kindly oblige me with an answer.— | Yours very sincerely | C. Darwin

Please to thank M^r | G. R. Gray | for his note to me.⁶