ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 
581 
inserted. Witli this flask there is no danger of injury to the bacteria by 
heating the culture through overcharge of current; any rise ot tem- 
perature is indicated by the current being cut off when this becomes 
excessive. . 
Compressorium.* — Prof. H. E. Ziegler describes his circular form 
of compressorium, through which a current of fresh water is made o 
flow and which has already been figured in this Journal. He also de- 
scribes a rectangular form constructed on the same principle hut large 
enough for the examination of relatively large objects, e.g. frog-larvae 
and small fishes. 
Heating Arrangement for Compressorium.t— Hr. R. Kantorowicz 
describes an arrangement for warming to a definite temperature the 
Fig. 48. 
water which is to he passed through Ziegler’s compressorium. + The 
vessel shown in the figure (fig. 48) contains a quarter of a litre ; into it 
* Zeitschr. f. wiss. Mikr., xiv. (1897) pp. 145-53 (4 figs.). Of; th^s Journal 
c 759- 1895, p. 367. f Zeitschr. f. wiss. Mikr., xiv. (1897) pp. 154 7 (2 fi Q s.), 
P ' \ Of. this Journal, 1894, p. 759 ; 1895, p. 367 ; and preceding abstract. 
