778 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
lace®, Pachyphyton bracteosum, a plant the anatomical structure and 
juices of which facilitate bacteriological experiment. Injection of pure 
cultivations of Bac. pyocyaneus into leaves of this plant gave results similar 
to those observed in animals, that is to say, the virus must be of a certain 
quality and quantity in order to produce deteriorating or lethal effects. 
Microscopical examination of leaves which had died showed that most of 
the germs were in the intercellular spaces, very few being observed within 
the cells. And, as might have been anticipated, none ol the phenomena 
of phagocytosis were observed, though undoubted evidence of degenera- 
tion was present. Chemical changes accompanied the anatomical ; the 
reaction of the leaf-juice of P. bracteosum is acid and equivalent to 
0*225 grm. H 2 S0 4 . In from 10 to 15 days this acidity fell to about 
half the quantity, and in general was proportional to the quantity of the 
cultivation introduced. 
It was also found that the leaves did not react to the influence of 
toxines as do animal tissues. No protection was afforded. 
Varieties of Diplococcus lanceolatus.* — Sig. P. Foa distinguishes 
two varieties of this bacterium (Pneumococcus of Frankel), which differ in 
their pathogenic action. The one ( Pneumococcus ) is oedematogenous or 
toxic; the other ( Meningococcus ) is fibrinogenous or septic ; but they are 
convertible into one another. 
Toxic Action of Cultivation Products of Avian Tuberculosis.! — 
M. E. de Freudenreich notes that animals injected with the products of 
avian tuberculosis die of emaciation and without the development of 
tubercle. The author had mixed 10 litres of milk, 300 grm. of a 
tubercle culture in glycerinized bouillon, and an emulsion of three 
cultures in glycerin-agar, and a cheese was made. After a period of 
maturation, rabbits were injected from this cheese, the animals dying in 
condition of extreme emaciation, but without tuberculosis. Control ex- 
periments were made with healthy cheeses for the purpose of ascertaining 
if products of maturation gave rise to similar phenomena, but the 
animals were unaffected, and the author infers that the toxins were 
introduced into the cheese when it was made. 
Microbic Synthesis of Tartar and Salivary Calculi.f — M. V. 
Galippe finds from microbiological analyses of concretions that the 
parasites contained therein are not accidental, but are the agents of the 
chemical phenomena. The parasites preserve their vitality for years, 
and may be isolated and cultivated. By the aid of chemical reagents 
the author determined that the organic skeleton of these salivary calculi 
was composed of a close network of micro-organisms, which had brought 
about the precipitation of the earthy salts. These micro-organisms vary 
according to the kind of calculus. From a chemical point of view 
salivary calculi are composed of phosphates and carbonates of lime and 
magnesia, like those which are formed spontaneously in the animal 
body. 
* Atti R. Accad. Lincei, 1893, pp. 403-5. 
f Ann, de Micrographie, v. (1893) pp. 31-3. 
X Comptes Rendus, cxvi. (1893) pp. 1085-6. 
