ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 245 



indicated that the virulence of B. icteroide* could be increased by re- 

 peated passages, and that infection through the stomach was practically 

 impossible. The author's results with the toxin were more marked and 

 more constant than Sanarelli's ; on these results a communication is 

 promised later. With regard to the action of serum of immunised ani- 

 mals, the author is of opinion that it possesses a bactericidal and also an 

 antitoxic action, the latter being the more powerful. Most of the immu- 

 nising substance was found in the liver and spleen, and emulsions of 

 these organs protected animals against yellow fever infection, even 

 when the blood had not yet acquired a protective power. The author 

 claims that his experiments lead him to the conviction that B. icteroides 

 is peculiarly adapted for infecting animals with yellow fever, and that, 

 as the symptoms during life and appearances of the organs after death 

 so closely resemble those in man, the disease can be most easily studied. 



Bacteriology of Typhus Fever.*— Dr. A. Balfour and Dr. C. Porter 

 examined the blood of nineteen living cases of typhus fever, and in every 

 instance found large numbers of a diplococcus after the blood had been 

 incubated for 24-48 hours; no other organism was found in the cultures, 

 and the diplococcus presented the same characters as the diplococcus 

 the observers had previously found in seven cases examined post mortem. 



The organism is about 2 /x in transverse diameter. It stains well 

 with the usual anilin dyes, and also by Grain's method. It grows well 

 in broth and milk, coagulating the latter in 24-18 hours. It is easily 

 cultivated on agar, blood-serum, and potato. Gelatin is liquefied in 

 5-8 days. The growth ou agar and potato is white. The optimum 

 temperature is 37°. 



Streptococcus amylivorus.f — Sig. L. Macchiata has observed in 

 macaroni flour, which may be made of wheat, rye, and pulse, starch- 

 grains which seemed corroded, and only faintly reacted in polarised light. 

 In these affected grains were noticed coccus forms with rosette arrange- 

 ment. The diameter of the individual cells was 1-1*25 //.. The cocci 

 stained well with basic anilin dyes. The author considers the cocci to 

 be the cause of the changes in the starch-grains, although he admits 

 that certain bacilli were also present. The action of the streptococcus 

 is a. sol vent one, for the affected meal showed 3 - 9 per cent, glucose, 

 while normal macaroni flour contained only 1 ■ 86 per cent. The quan- 

 tity of acid in the meal was also greater than in the normal. Pure 

 cultures of Str. amylivorus were obtained. 



Formation of Chinon in Streptothrix Cultures.^ — Prof. M. W. 

 Beijeriuck had his attention drawn to the formation of chinon (C 6 H 4 2 ) 

 by Str. chromogena Gasperini, owing to the fact that the gelatin browned 

 by Str. chromogena in a culture introduced into pepton solutiou was 

 turned black by ferric salts. It was also found that the culture-gelatin 

 of old gelatin-cultures is insoluble in boiling water, just as when free 

 chinon or a chrome salt had been allowed to act on the gelatin in the 



* Edinburgh Med. Journ., v. (1899) pp. 141-4 (5 figs.). 



t Bull. Soc. Dot. Ital., 1899, pp. 48-53. See Ceutralbl. Bukt. u. Par., 2" Abt., 

 v. (1899) pp. 821-2. 



X Ceutralbl. Bakt. u. Par., 2" Abt., vi. (1900) pp. 2-12. 



