584 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Mud Collector.* — Dr. C. J. Cori describes an apparatus for collect- 
ing tbe fauna from the surface of mud at the bottom of ponds. The 
glass rod R (fig. 50) is fixed to a bamboo rod, and is provided with a 
tightly fitting cork K, and an indiarubber ball B. On pulling the cork 
out by the string S, the escape of air causes the water to rush into the 
tube ; on further pulling the string, the mouth of the tube is closed by 
Fig. 50. 
the ball B. A form with a metal, in place of a glass, tube is figured. 
A further modification, suggested by Prof. Hatschek, for use with a 
cable in deep water, is described. A greater lowering of the line than 
shown in fig. 51 a, causes the projection Z on the tube to become dis- 
engaged from the weighted hook H, as seen in fig. b. When the line is 
pulled, the cork is withdrawn from the tube, and a further pull causes 
the tube to be closed again by the india-rubber ball, as in fig. c. 
Cultivation of Amoeba. f — According to Prof. P. Frosch, living 
bacteria are necessary for the proper growth and sustenance of Amoebae, 
though certain media are more suitable than others. The one preferred 
is composed of 0*5 grm. agar, 90 grm. tap water, and 10 grm. alkaline 
bouillon. Upon this, luxuriant cultures of an Amoeba derived from 
garden earth were constantly obtained. In these bacteria were always 
demonstrable, and the author’s view is that successful cultivation of 
Amoeba depends almost entirely on the bacteria supplied. 
Silk-Glue as a Medium for tlie Cultivation of Bacteria.J— In raw 
silk there exists a peculiar adhesive substance which imparts to the 
* Zeitschr. f. wiss. Mikr., xiv. (1897) pp. 184-9 (3 figs.). 
t Centralbl. Bakt. u. Par., l te Abt., xxi. (1897) pp. 926-32. 
X Op. cit., xxii. (1897) pp. 122-4. 
