Microscopic examination of a drop of blood from the finger of a patient with lymphadenorua of long standing, revealed several interesting phenomena. The examination was made with a B. and L homogeneous immersion objective, N. A. 1.43, and Zeiss' compensating eye-pieces, giving a magnifying power of 800 to 2,400 diameters. Lower powers are of little use in examining blood corpuscles. The drop of blood was placed upon a thin cover-glass, which was quickly dropped upon a slide and gentle pressure made upon it, so as to obtain a thin layer.
A little more than a year ago, in an essay read before the California State Medical Society, and published in its Transactions, I reported my observation upon the structure of normal blood corpuscles, as seen in a solution of bichromate of potass. These observations showed a great difference in size, shape and activity among the corpuscles, corresponding, in all probability,