(566 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the bacteria of necrosis. The products of decomposition which result 

 from the destruction of tissue independent of any action of bacteria 

 have no pathogenic properties. 



Tenacity of Life in Micrococci.* — MM. Pcrroncito and Airoldi 

 experimented on Micrococcus ambratus, the cause of pneumonia in 

 calves, and on the Pneumococcus of the horse, in order to ascertain the 

 relative lengths of time for which they could bo kept alive. On one 

 glass plate was spread some pure culture of M. ambratus ; and on a 

 second plate a similar culture, to which was added some sterilized 

 water. These were then placed in a water-bath, at a temperature of 

 35° C. Each day a small portion was taken from each culture and sown 

 in a tube containing gelatin. So long as the Micrococci remained 

 alive, they grew and formed small characteristic spots. Micrococcus 

 from the pure culture remained alive at tho sixteenth day ; the other 

 was dead on the thirteenth day. Pneumococcus, treated with sterilized 

 water, died very much sooner — on the tenth day. Heated to 50° C, in 

 the dry state, both were dead at the end of an hour. Tho authors 

 conclude that Micrococcus resembles the non-spore-forming bacteria 

 more than does Pneumococcus, so far as resistance to high temperatures 

 is concerned. 



Behaviour of the Spores of the Schizomycetes to theAnilin-dyes.t 

 — Herr H. Buchner had already pointed out that spores of Bacillus 

 subtilis which did not take up any anilin-stain on simply drying on 

 tho cover-glass, did so energetically when killed by heating in the 

 dry or moist way, or by treatment with pure concentrated sulphuric 

 acid or strong potash-ley. The same phenomenon occurs also in the 

 sporiferous distemper-filaments if these are dried on the cover-glass, 

 then slowly passed through the flame, moistened for a few seconds 

 with concentrated sulphuric acid, and finally washed with water and 

 stained by gentian-violet. The filaments then have a distinctly 

 septated appearance, the separate cells are either somewhat thick and 

 slightly stained or of normal width and strongly tinged, the spores 

 intensely so. The remarkable fact is then seen that the spores, which 

 previously lay in the vegetative cells of the filament, are driven out 

 of them by the action of the sulphuric acid, some of them lying free 

 by the side of the cells, some still adhering to their side-walls, in the 

 act, as it were, of escaping. Precisely the same appearance is seen in 

 Bacillus subtilis, which the writer regards as a fresh confirmation of 

 the morphological identity of these two forms. 



The author explains this behaviour of the spores of the Schizomy- 

 cetes towards anilin-pigments, on the one hand by the well-known fact 

 that living protoplasm does not take up any pigment, on the other 

 hand by his experiments, which show that the power of germination 

 of the spores is destroyed by the same degree of heat which brings 

 about their staining. He does not, however, agree with the hypo- 

 thesis of Koch that the strongly refringent substance of the spores is 



* Arch. Ital. Biol., vii. (1886) p. 341. 



t SB. Gesell. f. Morph. u. Physiol. Miinchen, 1885, 4 pp. (1 fig.). See Bot. 

 Centralbl., xxvi. (1886) p. 55. 



