ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 269 



three to four days, and on microscopical examination the bacteria were 

 found to have undergone enormous increase, rods with spores being 

 copiously developed ; Clostridium had dissolved the middle lamella of 

 the cell-membrane, so that the connection between the cells was de- 

 stroyed. This destructive process, which is here so rapidly completed, 

 proceeds only slowly during the resting period of seeds, because moisture 

 is a requisite for the development of bacteria. 



Varieties of Koch's Comma Bacillus.* — Dr. T. Zaslein, who has 

 directed his attention to the varieties of Koch's comma bacillus, has 

 obtained the following results. (1) The variety usually cultivated 

 grows on plates in the way described by Flugge. (2) There exist 

 varieties which grow more strongly at lower temperatures than the 

 freshly imported bacillus, and die earlier at lower maximum tempe- 

 ratures, and at the body temperature the course of their development is 

 hastened. (3) Bacilli obtained from simultaneous European epidemics 

 now behave differently. (4) A bacillus which was grown for a month 

 strictly according to Koch's procedure afterwards became altered in the 

 same medium. (5) The changes which Koch's bacillus has shown take 

 place gradually and irregularly, but may be influenced by artificial 

 cultivation. (6) The author's experiments have not shown that the 

 cholera bacillus, as far as regards the formation of varieties, is not subject 

 to other laws than those laid down by Darwin for plants and animals in 

 general. (7) The formation of definite varieties may take place without 

 artificial cultivation. 



Spore-formation in the Bacillus of Typhoid Fever.t — Dr. Pfuhl 

 followed in his investigation the method previously used by Buchner, 

 who, to ascertain the nature of these polar bodies, suspected of being 

 spores, first examined their behaviour towards certain pigments, then 

 their resistance to drying and high temperatures, and lastly their capa- 

 city for germination. The conclusion the author arrives at is the same 

 as Buchner's, viz. that these supposed spores are not spores at all, but 

 are, rather, a retrograde condition, or kind of involution form. As the 

 author's method and his conclusions are the same as Buchner's, already 

 noticed in this Journal, | there is no need to give the details. 



Staphylococcus pyosepticus.§ — MM. J. Herlcourt and Ch. Eichet 

 found in a cutaneous abscess of a dog a microbe which in form, size, 

 colour, reaction, and biological characters is allied to Staphylococcus 

 pyogenes alhus, but is distinguished therefrom by the following dif- 

 ferences : — (1) In fluid cultivations (peptonized meat broth) it grew on 

 the surface, forming whitish colonies, which pass away into viscid fila- 

 ments, while S. pyogenes alhus causes all the fluid to become cloudy, and 

 does not form any special collections on the surface. (2) It is more 

 septic and virulent than S. alhus. One or two drops injected under the 

 skin killed a rabbit (2 kg.) in about 24 hours, while S. alhus only killed 

 rabbits with stronger doses and after a longer time, (8) The one or 

 two drops injected subcutaneously produced a gelatinous transparent 

 oedema. It begins its development one or two hours after inoculation, 

 and attains its maximum in 24 hours. S. alhus causes suppuration, but 

 without the oedematous swelling. In animals which do not succumb in 



♦ Deutsch. Med. Ztg., 1888, Nos. 64 and 65. 



t Oentralbl. f. Biikteiiol. ii. Parasitenk., iv. (1888) pp. 769-76. 



: 1888, p. 1016.. § Comptes Rendus, cvii. (1888) p. 690. 



