Dear Sir,

I beg to thank you for your very kind and appreciative letter, & with regard to your query about the difference in the shading of the spots of the Argus being an optical illusion, I can assure you that is not the case, the markings being quite fixed & the only illusion is that produced by nature in making flat surfaces appear convex.¹ I have a feather taken from close to the bird’s body & also one of those farthest from it; in the former the spots are thus & in the latter=

M^r Tegetmeier of “the Field” will get the block stereotyped for you without charge & has kindly promised that it shall be ready soon. I told him of your wish that the Gold pheasant’s feathers should be cut out & am sorry you cannot find room for them, if in reconsidering the matter you should alter your mind please let me know at once.² In “the Student” you will find a sketch of this beautiful bird with the collar expanded.³ The only condition M^r Tegetmeier mentioned was that the cut should be alluded to as having been taken from “the Field”⁴

I remain, | Dear Sir, | Yours faithfully, | T. W. Wood.

Charles Darwin Esq. F.R.S. &c— &c—