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SUMMARY OF CURRENT RESEARCHES RELATING TO 
Atlantic, characterised by having four terminal setae ; and points out that 
West’s monotypic genus Attheya has been erroneously regarded as 
nearly allied to Bhizosolenia, whereas, in reality, the former genus 
belongs to the Eaphideae, the latter to the Cryptoraphideae. 
Movements of Oscillatoriacese. — Herr K. Kolkwitz * describes in 
detail the nature of the oscillating movements in several species of 
Spirulina and Oscillatoria. These are of two kinds, a movement of 
nutation and a movement of rotation ; the two movements may be ex- 
hibited in the same filament, one end of which may rotate, while the 
other nutates. 
Herr C. Correns f offers a somewhat different explanation, from 
observations made chiefly on Oscillatoria princeps . The outer wall of 
the cells exhibits a distinctly reticulate structure. The outer layers 
have a marked positive tension. No movement could be detected in 
the cytoplasm. The direction of the torsion may be to the right or to 
the left, but is constant in the same species. The funnel-formation at 
the end of creeping filaments is due to a curvature (often very slight) 
of the extremity, combined with the resistance of the water. The author 
never observed any movement of nutation. The filaments move only 
when closely attached (not merely iii contact) to a solid substance. 
External granules remain but slightly attached to the filament, and 
may move along it, the movement being quite as rapid along isolated 
dead cells. The author concludes that the filaments excrete a colourless 
jelly, which surrounds them in the form of a very soft sheath. They 
never swim freely in the water, the sheath taking no part in the move- 
ment. The filament may consist of active and inactive zones. The 
movements cannot, he considers, be attributed either to cilia, to a peri- 
pheral layer of pi-otoplasm, or to the expulsion of water. 
B. Schizomycetes. 
Behaviour of Bacteria to Chemical Reagents.f — Herren Th. Paul 
and B. Kronig made experiments for the purpose of testing the effects of 
various acids, bases, oxidising agents, and metallic salts, on bacteria, the 
bacteria employed being Staphylococcus pyogenes aureus and the spores of 
Bacillus anthracis. The salts of mercury, gold, and silver were found to 
exert a specific poisonous effect, while those of platinum had little, if 
any action. The disinfecting action of metallic salt solutions, in which 
the metal is present as a complexion, is very small. The effect of mer- 
curic chloride is greatly decreased by the addition of sodium and other 
chlorides, but is not affected by other salts, such as sodium nitrate. The 
acids only act as disinfectants in concentrations of the gram molecular 
weight per litre, and exhibit a specific action which is not proportional to 
the concentration of the hydrogen ions. The weak organic acids appear to 
act according to the degree of dissociation. The action of the hydroxides of 
lithium, sodium, and potassium is about equal, and that of ammonium 
very slight. Of the ordinary agents, nitric acid, chromic acid, chloric 
acid, and permanganic acid, act in the order stated. The halogens have 
* Ber. Deutsch. Bot. Gesell., xiv. (189G) pp. 422-31 (1 pi.). 
+ Op. cit., xv. (1897) pp. 139-48. 
% Zeit. Physikal. Cliem., xxi. (1896) pp. 414-50. See Jouru. Chem. Soc., 1897, 
Abstr. p. 155. 
