than the inner ones, but it is at times convenient to have material of different depths of staining. After the process has continued long enough—the nuclei at least should be very distinctly colored—the material is transferred into a fluid containing glycerine five parts, water and alcohol each two parts, acetic acid one part. Here it may remain about twenty-four hours, and finally it is to be preserved in a similar mixture containing but a trace of acetic acid. I hold acetic acid of varying strength diluted with glycerine in high esteem in such investigation. It does two things, removes the superfluous stain and softens and clears up the connective tissue. Thus treated, the material is ready for examination. The tissues thus prepared may be hardened in alcohol and sections cut, but this will not aid much in the investigation of the questions that interest us. For this purpose teasing and compression with the cover glass are mainly to be relied upon. It is to be commended to isolate one of the little lobules the gland is composed of, because thus we certainly have ready for examination all the elements making up the gland. The little root which connects the lobule with the rest of the gland will consist of the duct, vessel and nerves supplying the lobule. Such a lobule is broken up with needles and by compression between slides. All these manipulations are to be carried on in glycerine. When the fragments are small enough they are examined with lower powers. The ducts in well injected specimens can be recognized by the rich supply of vessels, the nerve-trunks by the arrangement of the nuclei. After examining larger fragments with lower powers, smaller ones are selected, subjected to pressure with cover glass, and examined with higher powers. By compression with cover glass, pushing from side to side, one can isolate almost any structure. One can also then make sure whether a fine fibre is really in connection with any other structure, or only lying above or beneath the same. The staining with the carmine will generally not attack the fine nerve fibres. To show these up I have used aniline blue dissolved in water. By these means I have brought out very plainly the nerve fibres, in nerve trunks, of considerable size, as well as those along vessels. I took the material prepared as described, broke up a little piece in fragments of the size of mustard seeds, and left them twelve hours in the blue fluid in a watch glass. Glycerine, if necessary, slightly acidulated, will remove the superfluous stain. I was very much pleased with the action of the aniline blue. Notwithstanding its physiological importance there is among the authorities as yet no uniformity of opinion on the histology of this gland, save that it belongs to the racemose glands, and is made up of epithelial cells.