CULTIVATION EXPERIMENTS. 215 



Gram's method. Recently Babes has made beautiful dry prepara- 

 tions by using a two per cent, solution of safrauiu in aniline oil, 

 followed by treatment with iodide of potassium. O. Israel "Ueber 

 Doppelfarbung mit Orceiu," Yirchow's Archiv, Bd. 105, S. 169) 

 has found that a solution of orcein in acetic acid stains the rays a 

 Bordeaux-red, while the filaments, if decolorization is not carried 

 too far, present a blue tinge. Baranski (Deutsche med. Wochen- 

 schrift, 1887) uses picrocarmine for staining fresh preparations of 

 actiuomyces bovis. A small amount of the contents of a yellow 

 nodule, or pus from the part, is spread in a thin layer on a cover- 

 glass, and dried in the air. The cover is then passed three times 

 through the flame of an alcohol lamp, care being taken not to over- 

 heat the preparation. It is then floated in the picrocarmiue solu- 

 tion, or a few drops of the staining fluid are placed on the cover. 

 The staining is finished in two or three minutes. The cover is 

 then carefully washed by agitating it in distilled water and alcohol, 

 and examined in water and glycerin. The fungus takes a yelk/w 

 color, while the remaining structure appears red. As regards the 

 history of the parasite outside the body, as yet only a few facts are 

 known. It is found in pig's meat and is peculiarly susceptible to 

 outside influences. It cannot be cultivated in pure water or one- 

 half per cent, solution of salt, such as is usually employed for 

 similar forms, as in these elements the fungi swell up and assume 

 fantastic shapes. Yirchow found them as small calcareous con- 

 cretions in the muscle fibres of the pig, and considered their flesh 

 highly dangerous food, unless well cooked. 



CULTIVATION EXPERIMENTS. It has been found extremely 

 difficult to cultivate the actinomyces, probably on account of the 

 usual culture media not being well adapted for its growth. The 

 first successful experiments were made by Bostrom (Jahresbericht 

 uber pathologische Anatomie, Baumgarten, 1886), of Giessen, upon 

 plates of blood serum and agar-agar, the fungus attaining its ma- 

 turity in five or six days, when it presented the typical appearances 

 of actinomyces as found in man. 0. Israel ("Ueber die Cultivir- 

 barkheit des Actinomyces," Yirchow's Archiv, B. 95, Heft 1) cul- 

 tivated the fungus successfully upon coagulated blood serum. The 

 culture grows very slowly, and the fungus often undergoes calcifica- 

 tion. He made the observation that water, glycerin, blood serum, 

 and weak saline solutions seriously impair the vitality of the fungus, 

 and believes that the effect of these agents on the actinomyces 

 explains the failure of previous culture and inoculation experiments. 

 Until recently, coagulated blood serum is the only medium upon 

 which the fungus has been successfully cultivated. If evaporation 

 is prevented, a thin velvety layer forms on the surface of the blood 

 serum in about eight weeks, in the vicinity of which, not before the 



