CHAPTER XXIX. 



CONNECTIVE TISSUES. 



Connective Tissue. 



681. General Stains for Connective Tissue, Connective tissue, 

 elastic tissue, and smooth muscle are all normally acido- 

 pliilous. Collagen, the distinctive element of connective 

 tissue, absolutely requires " acid ; dyes for the production 

 of a permanent stain, whilst elastic tissue and muscle will 

 also fix " basic ' dyes. Collagen has a special affinity for 

 Siiurefuchsin and Wasserblau. Elastin has a strong affinity 

 for acid orcein, whilst muscle has no special affinity for 

 either, but stains energetically with picric acid. 



Picro-saiirefuchsin is much used and very convenient as a 

 general differentiating stain, but not to be recommended for 

 cytological detail. See SCHAFFER, Zeit.' iris*. Zool., Ixxx, 

 1905, p. 176. 



E. and T. SAVINI recommend BENDA'S picro-saurefuchsin, 

 299. 



EHKLTCH-BIONDI mixture gives connective tissue red, but 

 smooth muscle redder still. 



UNNA'S Wasserblau-orcein for distinguishing connective 

 tissue and muscle has been given, 676. It works after all 

 fixatives. Stain long, and dehydrate preferably with acid 

 alcohol. 



FREE HORN (Amer. Hon. Mic. Journ., 1888, p. 231) recom- 

 mends (for sections) picro-nigrosin, made by mixing 5 c c. of 

 1 per cent, aqueous solution of nigrosin, with 45 c.c. of 

 aqueous solution of picric acid. Stain for three to five 

 minutes, wash with water, and mount in balsam. Connective 

 tissue blue, nuclei blackish, the rest yellowish. 



RAMON Y CA.TAL'S picro-indigo-car-mine gives connective- 

 tissue fibres dark blue, with red nuclei. 



S. MAY (Sifzl,. k. Al-a,l. Wi**., Ixxxv, 1882, p. f>9) 



