Down Farnborough Kent
Sept. 13th
My dear Sir
I thank you much for your two notes & am quite sorry that you shd. have had the trouble of writing two.— This note requires no answer & can give no trouble.— As Leydig seemed a puzzler to reach, I have sent a copy to Kölliker instead of to him, & to C. Vogt,1 & now all my copies are gone, & once again I thank you for your very valuable assistance.
I write now chiefly to say that if time & inclination leads you to look at any Balanus, do pray look at cementing apparatus, I am sure you wd. find it curious & worth looking at, & I shd. much like some naturalist to see it.2 If you are so inclined do not look at the coast Bal. balanoides, but a (young) white Balanus Bal. crenatus common on crabs & shells from deepish water: remove shell, leaving [c.] basis attached, & then dissolve it with its calcareous support in weak acid, then look with compound microscope & see antennæ of pupa, wonderful cement-glands & cement-ducts.
If you do anything more, do look at my acoustic vesicle,3 eyes & nervous system in the large Bal. perforatus so common at Tenby. I have only casually looked at these parts in these species.—
My dear Sir | Pray believe me | Yours sincerely | C. Darwin
Pray give to whomever you like, the second copy of my Book which you have.—4
If you stumble on Scalpellum vulgare do look at the Comp. Males.—
Please cite as “DCP-LETT-1592,” in Ɛpsilon: The Charles Darwin Collection accessed on