My dear M^r. Darwin

You must have been surprised at receiving no answer to your letter of Sep 22^d. and I am afraid may have been inconvenienced by my silence, but the fact is that I only returned yesterday from Germany, where, as I was rapidly moving from place to place, no letters were forwarded to me, and on passing through London to transact some Museum Business yesterday afternoon I found your letter with many others, awaiting replies, and have brought them on here, where I remain for a few days before beginning regular work in London again.¹

As you know, it always gives me great pleasure to be able to give you any information in my power, and I hope you will always make use of it, with or without my name just as you think may suit your purpose, or advance the cause of science best.

With regard to the statement about the Cetacean larynx, there is however a difficulty in making use of it in any argument, the facts are not yet clear—though I have often as you say, suspected that the elongated glottis is withdrawn from the posterior nares during deglutition, I have no proof of it, and Huxley is, or was the last time I talked to him on the subject, of a contrary opinion.²

It is perfectly obvious that such an arrangement unless required for some other more important purpose, as in the young marsupials, must be inconvenient and would therefore in all probability disappear in the adult.³

I must again apologize for having kept your MS. so long, and remain | most truly yours | W. H. Flower.