554 SUMMARY OF CURRENT RESEARCHES RELATING TO 
serve to explain the different appearances observed in the case of dif- 
ferent diatoms. The case of those valves which show the system of 
fibrils discovered by Mr. T. F. Smith is illustrated by a diagram, in 
which the thick projecting ends of the cell-walls are represented as 
detachable. The appearance of spines and complicated rosette patterns 
exhibited by some diatoms ( Arachnoidiscus , Isthmia, Coscinodiscus oculus 
iridis ) is explained by the author by the cups of the alveoles not being 
simple membranes stretched from wall to wall, but being supported 
within by a system of converging brackets springing from the sides of 
the alveoles. 
The paper is illustrated by sixteen of Mr. T. F. Smith’s later photo- 
micrographs. 
Aphanizomenon flos-aquae.* — According to Herr F. Ahlborn, this 
“ flos-aqufe ” is greatly dependent for its sustenance on nutrient material 
supplied to it in the form of gas-bubbles; hence in shallow water it 
very soon falls to the bottom and there perishes. The filaments are 
endowed with two kinds of motion — a spasmodic oscillating movement, 
and a gliding motion in a forward direction. 
• 
B. Schizomycetes. 
Action of the Rontgen Rays on Bacilli.f— M. F. Berton confirms 
the statement of previous observers that the Rontgen rays have no 
inhibitory effect on the toxic properties of the diphtheria bacillus. 
Bacterial Infection by Air-sown Organisms.f— Mr. H. T. Brown 
and Mr. G. H. Morris were able to trace to its source a case of bacterial 
infection in a brewery, the beers of which occasionally became ropy or 
viscous. The organism was a small coccus occurring in the dyad and 
tetrad forms. Though this organism was invariably found in all 
samples of ropy beer, the authors only succeeded once or twice in 
making sterile beer become ropy by infecting it with pure cultures. 
The production of viscosity would therefore seem to be dependent on 
certain conditions of nutriment not present in all beers. 
Bacteria and Carbonated Waters.§ — Mrs. G. C. Frankland remarks 
that there is considerable divergence of opinion as to the precise 
hygienic value with wdiich the carbonation of water can be credited. 
Some authorities state that in such waters the number of bacteria 
steadily declines, while others again have observed distinct multiplica- 
tion of the bacteria present. There is no reason to doubt the accuracy 
of either of these results, for widely different types of water have been 
used. It is clear that some bacteria have rapidly disappeared in aerated 
waters, while others are endowed with fabulous powers of multiplication 
and longevity. The researches of Dr. Abba on the use of siphons show 
that they may often be a source of real danger ; not only are they left 
unsterilised after use, but they are neither washed out nor even com- 
pletely emptied; hence a deposit is always present, which furnishes 
* Verhandl. Naturwiss. Yer. Hamburg, ii. (1895) pp. 25-36. See Bot. Centralbl., 
Beih., vi. (1896) p. 86. 
f Comptes Rendus, cxxiii. (1896) p. 109. Cf. this Journal, ante, p. 438. 
t Journ. Fed. Inst. Brewing, i. (1895) pp. 14-21. See Journ. Chem. Soc., 1896, 
Abs'r., p. 321. § Nature, liv. (1896) pp. 375-6. 
