652 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
his agreement with Gomont,* rather than with Borzi, in sinking the 
genus Lyrigbya in Oscillaria. The presence of a gelatinous sheath in 
species of the latter genus is so frequent that it cannot be relied on in 
distinguishing Lyngbya from Oscillaria. Kiitzing’s genus Phormidium 
must also be reunited to Oscillaria. 
The special colouring-matter of the Cyanopliyceae, phycocyanin, is 
soluble in water, but insoluble in alcohol or ether ; it differs also from 
chlorophyll in not being acted upon by solar light ; other micro- 
chemical reactions of this substance are given. The author does not 
agree with Borzi f that the straight hormogones are always destitute of 
a gelatinous sheath, those of Lyngbya Borziana frequently display one 
evidently. Microchemical reactions show that the gelatinous sheath of 
the Oscillariacem does not consist of cellulose or of protoplasm, but 
that it seems to have some relationship to the cutin of higher plants. 
The formation of spores appears to take place only at certain times of 
the year. 
j3. Schizomycetes. 
Bacillus of Cholera in Soil.J— Prof. V. de Giaxa draws the fol- 
lowing conclusions from his experiments with the cholera bacillus on 
soil. When the cholera bacillus enters a soil rich in common bacteria, 
even though it find conditions favourable to its existence and reproduc- 
tion, it rapidly succumbs in the struggle which takes place between 
itself and the other bacteria. The latter increase in number, and this 
increase is rendered possible as far as the deeper layers of the soil are 
concerned by the addition of nutrient material which agrees with them, 
and also modifies the condition of the ground. 
Should the cholera bacillus enter in relatively large numbers a soil 
which is inhabited by few ordinary bacteria, not only its preservation, 
but also its reproduction become possible, until an increase of the 
common bacteria takes place from the penetration of the soil by 
nutritive matters which enter along with the pathogenic bacteria. 
Germicidal action of Blood-serum and other Body Fluids.§— The 
doctrine of phagocytosis, invented by Metsehnikoff, and claiming 
that bacteria are destroyed by certain cells (phagocytes), has been 
recently opposed by the conjecture that it is the fluid constituents of the 
blood which really furnish the destructive agent. Dr. T. M. Prudden 
has made experiments with two pathogenic bacteria, B. typhosus and 
Staphylococcus pyogenes aureus , on blood-serum and other body fluids. 
The experiments were conducted in the usual manner and with the 
usual precautions, and as the result thereof it was found “ that fresh 
blood-serum possesses, though in different degrees in different animals, 
and in varying potency with the different bacterial species, a most 
marked germicidal power ; that a similar germicidal power resides in 
fresh human non-inflammatory transudations. That this power is not 
directly associated with the formed elements of the blood or transudates, 
* Cf. this Journal, 1889, p. 784. f Cf. this Journal, 1887, p. 448, 
t Annales de Micrographie, ii. (1890) pp. 222-51. 
§ Medical Record, Jan. 25, 1890. 
