ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



497 



B 



Cut the millboard into pieces 1 in. square, and punch out the centres 

 with a | or f gun-wad punch. Take a strip of perforated zinc 6 in. by 

 2£ in., and bend down 1 in. of the ends to a right angle to make rests 

 for the slides while in the moist chamber. When required for studying, 

 say, the spores of a coprophilous fungus, place one or more of the 

 punched-out squares of millboard between two pieces of glass, with a 

 weight on top, and soak in water for some hours. According to the size 

 of the drop required take one or more of 

 the squares, and after squeezing out the 

 excess of water place in the centre of a 

 slide. Then take a cover and ring a very 

 thin smear of soft paraffin or vaselin just 

 a shade smaller than the aperture in the 

 millboard. In a clean capsule put a little 

 of the nutrient medium and mix therein 

 the spores ; from this remove with a glass 

 rod or dropper sufficient to form a drop 

 and place in the centre of the ring, and 

 then invert over the perforation in the 

 millboard. Next place three or four 

 layers of blotting-paper on the bottom 

 of the soup-plate with sufficient water to 

 saturate them, on these the zinc support, 

 on the latter the slide with the hanging- 

 drop, and over all the bell-jar. The fore- 

 going procedure affords a satisfactory and 

 easy method for studying the growth aDd 

 development of the lower organisms, more 

 particularly algae and fungi. 



Simple Apparatus for Cultivating 

 Anaerobes in Test-tubes.* — W. Omeli- 

 anski has devised a simple and handy 

 apparatus for anaerobic tube-cultures. It 

 eonsists of two parts (fig. 105), a cylin- 

 driform vessel A and a cap B. The upper 

 end of A is choke-bored, and its base ex- 

 panded to ensure stability. The height of 

 the whole apparatus is 20 cm. ; the dia- 

 meter of A in the middle is 1*8 cm., and 

 at the base 8 cm. The cap B is ground Fig. 105. 



so as to fit accurately over the narrowed 



upper end of A. The upturned collar with everted rim C C, which forms 

 a sort of cup or receptacle for mercury, has a diameter of 5 ■ 5 cm. When 

 required for use, the ground surface of the cap is smeared with a mix- 

 ture of 1 part wax and 2 parts vaselin, and then a mixture of 10 ccm. 

 of 12-5 p.c. caustic potash and 10 ccm. of 5 p.c. pyrogallol solution 

 is poured into the bottle. The test-tube (diameter 16 mm., length 

 16 cm.) containing the culture is then inserted, and the cap put firmly 

 on. The cup is then filled with mercury in quantity sufficient to 



* Centralbl. Bakt., 2" Abt., viii. CI 902) pp. 711-3 (1 fig.). 



