Van Gieson’s is the best general stain for both striped and unstriped muscle, as it differentiates the muscle perfectly from the connective-tissue. Mallory’s reticulum stain may also be used for the same purpose. For the study of myoglia fibrils the tissue must be fixed within a few minutes after its removal from the living body. Autopsy material cannot be used. These fibrils can be demonstrated by Mallory’s fibroglia stain, or by Mallory’s phosphotungstic-acid hæmatoxylin stain for neuroglia. (See below.) IX. NERVOUS SYSTEM. It is impossible in a book on general pathologic technic to consider all of the numerous staining methods that have been devised for the study of the nervous system. I have attempted, therefore, to pick out the best selective methods for the staining of the more important nervous structures, so as to cover adequately the general held of nervous pathology. Formol has now replaced Müller’s for the preliminary fixation of nervous tissue, because of its quick action, and because after its use chromic acid may be employed to mordant the tissue, when it is desired to use certain staining methods requiring such mordanting. _Celloidin imbedding_ is preferable, although paraffin may be used for general work. _General stains_, such as _hæmatoxylin and eosin_, and _Van Gieson’s_ are used for general impressions. 1. =METHODS FOR STAINING GANGLION CELLS.= A. Lenhossék’s Method. 1. Fix in equal parts of saturated watery picric acid and mercuric chloride (Rabl’s mixture); after-harden in absolute alcohol; imbed in paraffin; cut. 2. Stain in saturated watery solution of toluidin blue, or thionin blue, for 12 hours. 3. Wash rapidly in water. 4. Differentiate carefully in absolute alcohol, or in aniline-alcohol (1-10). 5. Carbol xylol; xylol (quickly); balsam. Nissl’s granules are blue. This method is easy, and the best for general work. B. Nissl’s Method. 1. Fix in 96 per cent alcohol for 2-5 days; mount tissue in gum arabic on block; harden in 96 per cent alcohol; cut; place sections in 96 per cent alcohol. 2. Stain in methylene-blue soap mixture (methylene-blue B 3.75 grms., Venetian soap shavings 1.75 grms., water 1,000 cc. Shake well. Keep 3 months before using. Shake and filter before using.), warming, until bubbles arise. 3. Differentiate in aniline alcohol (aniline oil 10 parts, 96 per cent alcohol 90 parts) very rapidly. 4. Arrange section on slide; dry with blotting-paper; cover with cajuput oil. 5. Blot; wash off oil with benzene. 6. Remove benzene; mount the wet section in xylol colophonium, slightly warming; press on cover, and remove excess of colophonium. Nuclei of ganglion cells light blue: granules dark blue. Toluidin blue, thionin, dahlia, Bismarck brown or neutral red may be used instead of methylene-blue, and often give better results.