ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 99 



peratures of 43°, 51°, and 73° respectively. All six species had certain 

 common morphological and biological characters. All were motionless 

 rodlets, easily stainable with anilin dyes and also by Gram's method. 

 All were aerobic, and their optimum temperature was 60°, though all 

 could grow at 70°, and none could develop© below 37°. One formed 

 spores, and another possessed a proteolytic diastase. The most interest- 

 ing was isolated from the spring with temperature 51°. This possessed 

 morphological and biological characters like Bacillus subtilis, and on 

 experimenting with an old laboratory specimen of the latter, the author- 

 ess found that it was capable of growing at 57°, though less freely than 

 at 37°. By gradually raising the temperature, the laboratory specimen 

 was found, at the thirtieth generation, to grow abundantly at 58°, but 

 stopped at 58° '5. After alluding to Dallinger's success in breeding 

 flagellate infusoria at 70°, the authoress expresses the hope that by fol- 

 lowing on similar lines B. subtilis may be cultivated at temperatures 

 above 58°. 



Denitrification Bacteria and Sugar.* — Herr H. Jensen attacks the 

 results obtained by Stutzer and Hartleb, who found that carbohydrates 

 (hexoses and pentoses) serve equally well with the salts of organic acids 

 as pabulum and source of energy to bacteria capable of decomposing salt- 

 petre.* 



The author has repeated Stutzer and Hartleb's experiments, and has 

 obtained diametrically opposite results. 



Action of Toxins and Antitoxins.f — After discussing the theory of 

 Ehrlich of the constitution of toxins and the properties of mixtures of 

 toxins and their antitoxins, M. J. Danysz states that he is of opinion 

 that the peculiar feature of the action of toxins and the properties of 

 mixtures of toxins and antitoxins, are not due to the splitting up of 

 the toxin into different substances more or less toxic, but simply to the 

 presence of phosphates in the mixtures in greater or less proportions, 

 according to the degrees of weakening (more or less advanced) of the 

 toxins. According to the proportion of the phosphates and other salts 

 contained in the mixtures (and in the tissue in the case of a living 

 animal), one and the same active substance may produce variable effects. 

 Hence the difference in the sensitiveness to, and the action of a toxin on 

 different species of animals. 



Bacteriology of the Gangrene of Tooth-Pulp4 — Herr F. E. Zierler 

 isolated from typical cases of gangrene of tooth-pulp a microphyte, 

 which, while presenting many of the characters of Bacillus gangrense 

 pulpae,§ differs therefrom in some essential particulars. The chief of 

 these are that the author's microbe has rounded ends ; it is not at all 

 pleomorphic ; it is very prone to form spores ; and in relation thereto it 

 is asserted that Arkovy mistook spores for a vegetative coccus form on 

 agar. Additional information relative to some biological characteristics 

 is supplied. Gas formation in saccharated media is copious ; most of 

 the gas is C0 2 . Neither indol nor sulphuretted hydrogen is produced. 

 In 2 per cent, grape-sugar-bouillon, acid is formed for the first seven 



* Centralbl. Bakt. u. Par., 2 t8 Abt., v. (1899) pp. 716-20. 

 t Ann. Inst. Pasteur, xiii. (1S99) pp. 581-95. 

 X Centralbl. Bakt. u. Par., l te Abt., xxvi. (1899) pp. 417-25. 

 § Cf. tliis Journal, 1S98, p. 579. 



H 2 



