ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
683 
diastatic ferments are produced, and gelatin is liquefied very slowly. 
Urea is decomposed through the agency of an unisolated ferment into 
ammonium carbonate. 
The vegetative cells pass through a swarming condition : these cells 
are short rodlets united occasionally into filaments. The swarming state 
passes after a time into a resting condition, in which the cells do not 
alter in form. Many of these cells are “ arthrospores,” as is evinced by 
their greater resistance to heat and drying. 
Streptococcus pyogenes.* — Prof. E. M. Crookshank points out that 
Streptococcus pyogenes is found not only in abscesses, but in scarlet fever, 
diphtheria, and other diseases associated with septic complications. 
Cultivations made under different conditions, chiefly of the medium, 
showed striking variations in the cultures and subcultures, not only 
macroscopicallv, but microscopically. It is evident, therefore, that such 
differences should be recognized and taken into consideration. The 
author’s conclusions were derived from the examination of cultures made 
from a single source, a case of Str . pyogenes Jiominis. 
Analogous results were obtained in cultivating Str. py. bovis , but 
when grown under exactly identical conditions the differences between 
these two organisms were very marked, and the author therefore con- 
cludes that they are distinct varieties. 
Non-identity of Streptococcus pyogenes and Streptococcus erysi- 
pelatosus.f — From a series of experiments made with Str. pyogenes and 
Sir. erysipelatosus , Prof. E. M. Crookshank finds that primary cultures 
of the two micro-organisms cultivated under precisely the same con- 
ditions differed in the size and character of the chains, in the size of the 
individual elements, in the greater opacity of the colonies of Str. erysi- 
pelatosus , in a greater tendency to confluence, and in a more rapid 
growth. 
The author found that the difference was most marked in broth- 
cultures. Abundant flocculi were formed by Str. pyogenes , and a powdery 
deposit, with a special tendency to form a granular adhesive film at the 
bottom of the culture-flask in the case of Str. erysipelatosus. Lastly, 
they differed in their power of resisting germicides. 
Products of Staphylococcus pyogenes.J — MM. A. Rodet and J. 
Courmont have obtained the following results from examining the pro- 
perties of the soluble toxic products of St. pyogenes : — Cultures sterilized 
by heat kill dogs in a few hours ; all the organs are much congested, 
and death is preceded by dyspnoea and lowering of the arterial pressure. 
Yery small doses are able to produce a chronic intoxication in rabbits, 
and the animals die in eight to ten days in an advanced cachectic con- 
dition. Cultivations filtered through porcelain are less poisonous, and 
their toxicity varies with the age of the culture, the time of filtration, 
and the length of the interval between filtration and application. A 
culture filtered a long time before is three or four times less virulent 
than when used directly after filtration. Notwithstanding this vanishing 
* Trans. 7th Internat. Congress Hygiene, ii. (1892) pp. 67-8. 
f Tom. cit., pp. 68-9. 
% Le Bulletin Med., 1892, p. 84. See Centralbl. f. Bakteriol. u. Purasitenk., 
xiii. (1893) pp. 532-3. 
