746 



SUMMAEY OF CUERENT RESEARCHES RELATING TO 



on artificial media failed. The method of examination was as follows : 

 A few drops of the culture were drawn up in a fine pipeite and examined 

 fresh either in a hanging drop preparation or under a cover-slip with 

 wax feet, and waxed round the edges. In this latter condition the 

 animals remained alive for 13 days. 



Grood permanent preparations were hard to obtain, owing to the small 

 numbers of the parasites and the large amount of gritty foreign sub- 

 stances in the fluid. For successful preparations the stains used were 

 Delafield's hsematoxylin, Heidenhain's iron-h^matoxylin, and Griemsa, 

 Observations of the living animal were often facilitated by intravitam 

 staining with neutral red. Brilliant cresylblau and methylen-blue were 

 of little use. 



Simple Method of Obtaining an Oxygen-free Atmosphere for 

 Cultivating Anaerobes.* — Stan. Ruzicka uses a Kipps' apparatus for 

 producing hydrogen, and gets rid of the remaining oxygen with pyro- 

 gallol and caustic potash. As indicator he uses a mixture of phenol 

 soda, grape-sugar, and indigo sulphate. 



Cultivation of Essential Anaerobes in a Vacuum.t — U. Biffi 

 employs the following apparatus (fig. 128) for the cultivation of anaerobes. 



This consists of a strong thick-walled 

 Erlenmeyer flask, of 250 c.mm. capa- 

 city, closed by a rubber cork, per- 

 forated by a short glass tube that 

 extends from the lower surface to 

 about 3 cm. above the top of the 

 cork ; this glass tube is inclosed by 

 rubber tubing about 8 cm. long, the 

 further upper end of which holds a 

 short piece of glass tubing about 

 2 cm. long, and which at its free end 

 is closed by wool. 



The flask is filled to one-third of 

 its height with broth, and into this is 

 plunged a thin glass tube 2-3 mm. 

 in diameter, and long enough to 

 reach from the bottom of the flask 

 nearly to the stopper ; this tube is 

 closed at the upper end, and serves 

 as a manometer to indicate the pres- 

 sure in the flask. The apparatus 

 is then sterilised, and all the tube 

 joints are smeared with Canada balsam. The broth is then slowly boiled, 

 and on the first appearance of small bubbles around the manometer tube, 

 the wool plug is removed from the outer tube. As soon as the steam 

 commences to escape strongly from the opening, the rubber tube is seized 

 with a pinchcock between A and B, and the whole is removed from the 

 heat, and the wool plug replaced. When the apparatus has cooled, it is 

 ready for use. The inoculation from the culture material is effected into 



* Archiv f. Hyg., Iviii., p. 327. See also Centralbl. Bakt. Ref., Ite Abt., xl. 

 (1907) pp. 308-10. t Centrabl. Bakt., Ite Abt., Orig., xliv. (1907) p. 280. 



Fig. 128. 



