My dear D^r Günther

Sincere thanks.— Your answers are wonderfully clear & complete.² I have some analogous questions on Reptiles &c. which I will send in a few days & then I think I shall cause no more trouble— I will get the Books, you refer me to.—³ The case of the Solenostoma is magnificent, so exactly analogous to that of those birds in which the female is the more gay, but ten times better for me, as she is the incubator.—⁴ As I crawl on with the successive classes I am astonished to find how similar the rules are about the nuptial or “wedding dress” of all animals. The subject has begun to interest me in an extraordinary degree; but I must try not to fall into my common error of being too speculative. But a drunkard might as well say, he would drink a little & not too much! My essay, as far as fishes, batrachians & reptiles are concerned, will be in fact yours, only written by me.—

With hearty thanks | Yours very sincerely | Ch. Darwin

Remember whenever so inclined how glad we shall be to see you here.—

Thanks for proof plates; I shall be very glad indeed to see the paper.—⁵