ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 79 



temperature being 34°-37° C. It is an essential aerobe, and does not 

 liquefy gelatin. The growth on most media is yellowish ; old cultures 

 exhale a disagreeable odour ; gas and indol are not produced ; experi- 

 ments on guinea-pigs with pure cultures reproduced the disease. The 

 post-mortem appearances varied with the duration of the disease and 

 with the method of infection. Positive results were obtained by 

 spraying the trachea, by injecting the bacteria into the thorax and into 

 the circulation. Subcutaneous injections were however followed by 

 abscess and recovery. Injections of filtrates of bouillon cultures gave 

 negative results. In general terms it may be said that B. pneumoniae 

 caviarum excites a pneumonitis with a focal or lobular distribution. 



Diphtheria in Horses.* — Dr. L. Cobbett expresses the opinion that 

 horses are probably peculiarly liable to diphtheria, and hence may have 

 no inconsiderable share in the dissemination of this disorder. This 

 idea receives confirmation from the well-known sensitiveness of some 

 of these animals to the action of the diphtherial poison. The author's 

 view was derived from finding the diphtheria bacillus in the nasal dis- 

 charge of a pony. An exhaustive examination of the characters and 

 toxins of the bacillus conclusively proved its diphtherial nature, and led 

 to the examination of other horses, in order to test if antitoxin were 

 present in their blood. Out of 13 animals, in 9 the antitoxin was found 

 to be present. From this the author infers that such animals had ac- 

 quired the disease naturally. 



Streptococcus decolorised by Gram's Method, f — J. Cottet and 

 H. Tissier isolated from cases of purulent cystitis and diarrhoea a 

 streptococcus which is decolorised by Gram's method. With the 

 ordinary anilin dyes it stains easily. The diameter of the coccus does 

 not exceed 0*5 /x. It grows under aerobic and anaerobic conditions, and 

 was cultivated on agar, gelatin, in bouillon and milk. No growth was 

 •observed on potato. Only a few streptococci which are decolorised 

 by Gram's method have been described, and the authors allude to four 

 only, from which theirs is distinctly different. 



Action of Anthrax on Carbohydrates. } — Mdlie. Napias has found 

 that anthrax easily attacks amylaceous and saccharine substances ; at the 

 expense of each it forms a fixed acid (lactic) and a volatile acid (acetic). 

 When the carbohydrate nutriment becomes scanty (sugar) or difficult 

 to attack (starch), the bacterium attacks the lactic acid which has been 

 formed, and consumes it in two stages : it leaves as residue some acetic 

 acid which is destroyed later, so that all the carbon of the original 

 carbohydrate substance is converted into carbonic acid. The bacterium 

 and the vaccines derived from it behave inversely, in regard to their 

 proteolytic and amylolytic properties; the proteolytic properties pre- 

 dominate in the virulent species, and the amylolytic in the attenuated. 



Effect of Acid-resisting Bacteria of the Tubercle Group on 



Animals. § — Dr. G. Mayer's experiments with acid-resisting bacteria of 



erele group were made by infecting cultures rubbed up with 



* Centralbl. Bakt, 1" Abt, xxviii. (1000) pp. 631-4. 



t C.R. Soc. de Biol., Hi. (1900) pp. 627-8. 



% Ann. Inst. Pasteur, xiv. (1900) pp. '232-47. 



§ Centralbl. Bakt., l'» Abt., xxvi. (1899) pp. 321-36 (;j figs.). 



