ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 75 



changed, though good growth takes place at the bottom. Litmus milk 

 is reddened in 24 to 48 hours. In all media the microbe forms long 

 chains, which in fluid cultures are wound up into skeins and bulls. 

 The diameter of the coccus varies from • 6 to • 8 /x. It stains well by 

 Gram's method. It quickly dies, so that it must be resown within the 

 week. It lasts longest in gelatin. 



Bacterium diphtherioides. This microbe was isolated from the 

 purulent secretion from a cow's udder. It has the following cultural 

 characters. It grows badly or not at all on gelatin, agar, and bouillon ; 

 grows well in milk at 37°, which is coagulated and acidified. It grows 

 best on blood-serum, which is slowly liquefied. At 37^ the colonies are 

 small, white, and roundish by the second or third day, and by transmitted 

 light are yellowish-brown and granular. Taken from serum cultures,, 

 the majority of the microbes are oval or spherical and show a central 

 deeply staining granule. The minority are club-shaped or transitional. 

 B. diphtherioides stains well with the ordinary anilin dyes, and especially 

 so by Gram's method. Intraperitoneal and subcutaneous injections into 

 guinea-pigs were followed by suppuration. Cultures require to be re- 

 sown within a week, the serum cultures retaining their vitality longest. 



Bacterial Flora of American Cheddar Cheese.* — Mr. J. Weinzirl, 

 who in conjunction with Prof. H. L. Russell had found previously 

 that the lactic acid bacteria predominated in American cheese, and that 

 the casein digesting forms were relatively few or absent, now records 

 experiments relative to the constancy and distribution of the bacterial 

 flora in American cheese. These experiments show that the lactic acid 

 producing group of bacteria is constantly present, though their exact 

 function cannot at present be positively stated. It seems probable 

 that they exei t considerable influence on the flavour of cheese. 



It is specially noted that when in small numbers B. acidi lactici 

 produces no untoward effects, but when it predominates it causes the 

 swelling or " huffing " of the cheese, which is highly detrimental to the 

 product. 



Bacillus microbutyricus.f — Dr. F. E. Hellstroni isolated from butter 

 a bacillus which he has named B. microbutyricus. The microbe is 1*2- 

 1-3 jx long and 0-2-0-3 /x thick. It is a straight rodlet with rounded 

 ends, and is quite motionless. On gelatin the growth is slow and of a 

 yellowish hue. The colonies are small and discrete, and the medium is 

 not liquefied. On agar the growth is quicker and the appearances are 

 very similar. In bouillon a bottom growth occurs, the sediment being 

 slimy and greyish-yellow. Glucose bouillon is slowly acidified without 

 gas formation. Milk is not coagulated, but the casein is after a time 

 gradually peptonised. Ou potato the growth is fairly rapid and of a 

 yellow colour. The bacillus is not pathogenic to mice, guinea-pigs, or 

 rabbits. It is stainable only with alcoholic solutions and not by Gram's 

 method. It grows better with than without oxygen. Spore-formation 

 was not observed. 



Koumiss Bacillus.:}: — Dr. D. Schipin isolated the Koumiss bacillus 

 in gelatin under anaerobic conditions. The colonies are whitish, and 



* Centralbl. Bakt, 2" Abt, vi. (1900) pp. 785-01. Cf. this Journal. 1897, 

 P- 571. t Turn. cit.. pp. (JS3-4 (1 fig.). ; Tom. cut., pp. 775-7. 



