338 CYTOLOGICAL METHODS. 



Studien iiber die Zelle, 1886, his Die Elementarorganismen, 

 Leipzig, 1890, and a paper in Arch. f. Anat. u. 'EntwickeL, 

 1892, p. 223; also Zeit.f. wiss. Mik., vii, 2, 1890, p. 199 ; ix, 

 3, 1893, p. 331; and L. and R. ZOJA, in Mem. R. 1st. Lorn- 

 bardo di Sci. e Lettere, xvi, 3, vii, p. 237. Omitting minutiae 

 and variations, it may be said that these granules may be 

 demonstrated by fixing for twenty-four hours in a mixture of 

 equal parts of 5 per cent, bichromate of potash and 2 per cent, 

 osmic acid, imbedding in paraffin, staining sections for a 

 minute on the slide held over a flame with a solution of 20 

 grms. of acid fuchsin in 100 c.c. of anilin water ( 101), and 

 washing out with saturated alcoholic solution of picric acid 

 diluted with 2 volumes of water, heat being used as before to 

 aid the differentiation, and finally clearing with xylol and 

 mounting in balsam. 



642. Mounting. For fresh objects you have so large a 

 choice of mounting media that you may take whatever liquid 

 gives you the best optical results. Sections of hardened tissue 

 should always (if possible) be mounted in damar (or colopho- 

 nium), not balsam, as the slightly lower index of damar or 

 colophonium solutions gives more powerful images of very 

 delicate details. If you have to deal with objects so delicate 

 that you have cause to fear mechanical injury to them on 

 putting them into damar, they may be mounted in thickened 

 turpentine (or cedar oil, but turpentine is preferable on ac- 

 count of its lower index). Rabl has lately been using methyl 

 alcohol as an examination medium for dehydrated objects; 

 but the preparations do not keep in this. Castor oil may be 

 tried (GRENACHER). I have not had good results with it. 



643. Other General Cytological Methods. 

 STRASBURGER'S Methods (see Arch.f. mik. Anat., xxi, 1881, p. 477). 

 USKOFF'S Nitric Acid Method (see Arch. f. mik. Anat., xxi, 1882, 



p. 292). 



PFITZNER'S Sulphate of Soda Method (see Morpliol. Jahrb., xi, 1885, 

 p. 54). 



TIZZONI (Bull delle Sci. Med. di Bologna, 1884, p. 259). 



BAUMGARTEN (Zeit.f. wiss. Mik., i, 1884, p. 415). 



BIZZOZERO (ibid., iii, 1886, p. 24). 



BABES (ibid., iv, 4, 1887, p. 470). 



ZWAARDEMAKER (ibid., iv, 2, 1887, p. 212). 



NISSEN (Arch.f. mik. Anat., 1886, p. 338) stains material fixed in Flem- 

 ming and sectioned, by the method of GRAM (see above, 102). 



