440 CHAPTER XXXIII. 



1>. 3; Zeit.f. wiss. Mik., xii, 1, 1895, p. 64, and KEOMPECHEE, ibid., xv, 

 1899, p. 458. 



797. Clasmatocytes, KANVIEK (C. R. Acad. des Sci., 1890). 

 A piece of suitable membrane (epiploon of mammalia, 

 mesentery of batrachia) is stretched secundum artem on a 

 slide, and a few drops of 1 per cent, solution of osmic acid 

 are allowed to fall on to it. After one or two minutes it is 

 washed with water and stained with concentrated aqueous 

 solution of methyl violet 5 B diluted with ten parts of dis- 

 tilled water. Glycerin may be added to make the prepara- 

 tion permanent, but does not succeed very well, as it causes 

 the stain to diffuse. Brunts glucose medium ( 421) would 

 probably be preferable. 



798. Elastic Tissue. Two of the most salient characters of 

 elastic fibres are that they have a great affinity for osmium, 

 staining with much more rapidity than most oth'er tissue - 

 elements, and that they are not changed by caustic soda or 

 potash. A further character is that they have a great 

 affinity for certain anilin dyes, especially Victoria blue. 



' For a review of the older methods of BALZEE, UNNA, 

 LUSTGAETKN, and HERXHEIMER, see the paper by G. MARTINOTTI 

 in Zeit.f. wiss. Mik., iv, 1, 1887, p. 31. 



The method of LUSTGAETEN has been given in 275. The 

 Colour used by him was called " Yictoriablau 4 A /' and this 

 may be important. 



The method of G. MAETINOTTI (loc. cit.) is as follows : Fix 

 in a chromic liquid, wash, stain for forty-eight hours in 

 strong (5 per cent. Pfitzner's) solution of safranin, wash, 

 dehydrate, clear, and mount in balsam. Elastic fibres are 

 stained an intense black, the rest of the preparation showing 

 the usual characters of a safranin stain. 



The staining will be performed quicker if it be done at the temperature 

 of an incubating stove (GEIESBACH, ibid., iv, 1887, p. 442). And FERKIA 

 (ibid., v, 3, 1888, p. 342) says that clearer preparations will be obtained if 

 the sections be left for a long time, say twenty-four hours, in the alcohol, 

 or be treated for a short time with very dilute alcoholic solution of caustic 

 ' potash. This decolourises more completely the ground of the preparations. 



Another safranin method, which seems to have the fault of requiring a 

 too minute attention to details, is that of MIBELLI, see Mon. zool. italiano, 

 1, p. 17, or Zeit.f. wiss. Mik., vii, 2, 1890, p. 225 (the report in Journ. Roy. 

 Mic. Soc., 1890, p. 803, is vitiated by a misprint). 



