X.—On the Existence of Acari between the Laminæ of Mica in Optical Contact.

Extract

In searching for crystals of titanium between films of mica, I was surprised to observe something resembling the remains of insects. Upon submitting the specimen which contained them to a more careful examination, I found, in different parts of it, five completely formed Acari, all of which were much smaller than those found in cheese, brown sugar, and damp bran, specimens of which I obtained for the purpose of comparison.