.316 SUMMARY OF CURRENT RESEARCHES RELATING TO 
the bacilli which in an alkaline solution lead to the production of that 
substance. (5) Diffuse daylight is unfavourable to pigment production. 
(6) Excess of certain substances which in themselves are favourable to 
growth and pigment production, checks pigment production, but does 
not interfere with growth. 
The author expresses his own opinion as follows : — that “since the 
pigment is of no discoverable advantage to the organisms possessing tho 
power of producing it, its production is probably purely accidental and 
not an essential vital act. The ‘ fluorescigenic function ’ is simply the 
expression of certain changes wrought by the organism upon the sub- 
stratum on which it lives. When the substratum contains certain 
compounds, the metabolic activities of the organism adjust themselves 
to these conditions, and the metabolic j)roducts differ correspondingly. 
It is purely a matter of accident, and of no physiological significance, 
that under certain conditions one of these metabolic products happens to 
be fluorescent.” 
Micro-organisms in Dunedin Water.* — Mr. A. G. Kidston-Hunter 
found an average of 30 non-pathogenic organisms per ccm. in Dunedin 
water; no pathogenic species were detected by any of the methods 
used. The principal organisms were : — (1) Bacillus aquatilis fluorescens. 
This is an aerobic short slender bacillus with rounded ends. The colo- 
nies resemble a fern-leaf with a lustre of mother-of-pearl. The gelatin 
is not liquefied. (2) The yellow bacillus. This exhibits in gelatin-tube 
cultures a yellow thread-like growth, which penetrates the medium 
in a lateral direction and liquefies it slowly, causing a funnel-shaped 
cavity wherein is deposited a golden-yellow slime. On gelatin-plate 
cultures the colonies are small, oval with serrated edges, and of a golden- 
yellow colour. (3) The orange-red water bacillus. This is a very 
slender bacillus, aerobic, does not liquefy gelatin, and forms on the sur- 
face of the medium red granular-looking colonies. 
Pathogenic Sarcina.t — Dr. Loewenberg isolated a sarcina from the 
secretion in the nasal fossa of a person suffering from ozaena. The 
sarcina is non-motile. It stains well and also by Gram’s method. It 
grows well on the usual media. The optimum temperature is incubation 
heat. When tartaric acid was added to nutrient media, no growth en- 
sued. The most suitable media were liquid ; and though growing well 
in milk, this liquid was not coagulated and remained alkaline. 
While in the original source the arrangement of the aggregates was 
typically cubical, in the solid cultivation media this was irregular, in 
groups or in chains. In the liquid media the grouping was typical. 
The sarcina is a potential anaerobe, and does not produce gas or 
odour. It is distinguished from other sarcinge by being pathogenic to 
guinea-pigs, white mice, and rabbits. 
Hew Butyric Acid Bacteria.^ — Herren A. Schattenfroh and B. 
Grassberger have found butyric acid bacteria in milk by heating a 
quantity for five minutes to half an hour in a steamer, and incubating 
the closed vessel at 37° C. By the next day lively fermentation had 
* Fourth Intercolonial Med. Congress, Dunedin, 1896, 7 pp. 
+ Ann. Inst. Pasteur, xiii. (1899) pp. 358-64. 
X Centralbl. Bakt. u. Par., 2 te Abt., v. (1899) pp 209-11. 
