352 CONNECTIVE TISSUES. 



752. Bielschowsky's SILVER METHOD (post, under " Neurofibrils ") 

 has been used for connective-tissue fibrils. SNESSAREW (Anat. 

 Anz., xxxvi, 1910, p. 401) employs it as follows : Tissue is hardened 

 in neutral formol and sectioned with a freezing microtome. The 

 sections are put for at least four days into iron alum of 2-5 to 10 

 per cent., changed daily. They are then silvered for thirty-six to 

 forty-eight hours in nitrate of silver of 10 per cent., then treated 

 with the oxide bath and reduced in formol of 20 per cent. Collagen 

 fibres grey, but fine connective networks black, nerve fibres un- 

 stained or only weakly stained. 



See also MARESCH, Zeit. wiss. Mik., xxiii, 1906, p. 356 ; STUD- 

 NICKA, ibid., p. 416 ; ZIMMERMANN, ibid., xxv, 1908, p. 10 ; LEVI, 

 Monit. zool. ItaL, 1908, p. 290 ; HEINRICH, Arch. mik. Anat., 

 Ixxiv, 1909, p. 786 (dentine) : INSABATO, Arch. Ital. Anat. Emb., 

 viii, 1909, p. 375 (silvers Flemming material) ; ATHANASIU and 

 DRAGOIU, C. R. Acad. Sci-., cli, 1910, p. 551 (Ramon y Cajal's silver 

 process, with alcohol fixation). 



Elastic Tissue. 



753. Elastic Tissue, Generalities. Elastic fibres have a great 

 affinity for osmium, staining with much more rapidity than most 

 other tissue elements. They are not changed by caustic soda or 

 potasfr. They are normally acidophilous, but are easily rendered 

 artificially basophilous by means of chromic acid or other mordants, 

 and then stain with great energy with basic dyes. Hence a group 

 of stains of which those of Lustgarten and Martinotti are types. 

 They have a natural affinity for orcein, whence stains of the Taenzer- 

 Unna type. 



For a review of the older methods of BALZER, UNNA, LUSTGARTEN, 

 and HERXHEIMER, see the paper by G. MARTINOTTI, in Zeit. wiss. 

 Mik., iv, 1887, p. 31 ; also Encycl. mik. Technik., art. " Elastin." 



754. Victoria Blue (LUSTGARTEN). See 289. 



755. Safranin (G. MARTINOTTI, loc. cit., 753). 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 black. 



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

 of an incubating stove (GKIESBACH, ibid., iv, 1887, p. 442). See also 

 FERRIA (iUd., v, 1888, p. 342). 



See also MIBELLI, Mon. Zool. Italiano, 1, p. 17, or Zeit. wiss. Mile., vii, 

 1890, p. 225 (the report mJourn. Eoy. Mic. 8oc., 1890, p. 803, is vitiated 

 by a misprint). Other basic dyes have been recommended. 



