NEUROGLIA AND SENSE ORGANS 561 



Prenant {l7itern. Monatsschr. Anat., ix, 1892, p. 28). Open 

 the cochlea in sokition of Flemming or of Hermann, and hx 

 therein for four to five hours. Avoid decalcification as far as 

 possible, but if necessary take 1 per cent, palladnnn chloride. 



Make paraffin sections. , i u,r 



Isolation preparations of the stria vascularis may be made by 

 putting a cochlea for a day into 1 per cent, solution of osmic 

 acid, then for four to five days into 0-1 per cent, solution ; the 

 stria may then be got away whole. 



Katz iZeit. wiss. Mik., xxv, 1908, p. Ill) fixes the inner ear, 

 opened, for one or two hours in 30 c.c. of 0-5 per cent osmic 

 acid with 5 drops of acetic acid, then adds 10 drops of acetic 

 acid and 60 c.c. of chromic acid (or platinum chloride) of 0-5 per 

 ■ cent, and leaves it for four days therein. He then rinses, puts 

 for twelve to twenty-four hours into pyroligneous acid or pyro- 

 gallol or tannin solution, decalcifies (not necessary for mice) 

 in 200 parts of water with 1 of chromic acid and 4 to 10 ot nitric 

 or hydrochloric acid, and imbeds in celloidin or sometimes 

 paraffin. 



Similarly WiTTMAACK, see § 1071. , • ,onc 



BiELSCHOWSKY and Bruehl [Arch. mik. Anat., Ixxi 1908, 

 p 27) fix the petrous in formol of 20 per cent., decalcify it in 

 nitric acid of 5 per cent., wash this out, and put back for a few 

 days into the formol, cut by the freezing method and silver by 

 the neurofibril method (§ 1021-twenty-four hours in nitrate ot 

 4 per cent., but only a few minutes in the oxide bath) 



Similarly Mullenix {Bull. Mus. Co7np. Zool. Harvard Coll., 



liii, 1909, p. 215). . 



Stein (Anat. Anz., xvii, 1900, p. 398) decalcifies in celloidm 

 by the method of Rousseau. So also Kishi {Arch. mik. Anat., 



lix, 1902, p. 173). ^ _ ^A r.A 



For staining, Ranvier {Traite, p. 991) employs his gold and 



formic acid method. , 



The bichromate and silver method of Golgi may be employed 

 with fceial or new-born subjects. The methylen blue mtra-vitam 

 method has given good results. For the higher vertebrates 

 the injection method should be employed. The Encycl. mik. 

 Technik., i, p. 511, recommends injection of 1 c.c. of 0-5 to 1 per 

 cent solution every five minutes through the vena femoralis 

 until the death of the animal. The cochlea then to be got out, 

 exposed to the air for fifteen or thirty minutes, and fixed for some 

 hours (overnight) in 10 per cent, ammonium molybdate with a 

 little osmic acid. It is then decalcified in trichloracetic acid of 5 per 

 cent, with a trace of platinum chloride, washing for twenty-four 

 hours and got into paraffin. 



For fishes and amphibia the immersion method will suthce. 

 Fraser {Ann. Otology, Khinology and Laryngology, xxxii, 1923, 



