500 SUMMARY OF CURRENT RESEARCHES RELATING TO 



appearance of brownish spots in the centre of the turnip, but in advanced 

 cases, the flesh of the turnip becomes quite black, only the rind being left 

 in its natural condition. Soft white rot is a more rapid disease, and con- 

 verts the whole turnip into a soft yellowish evil-smelling pulp. This 

 disease is caused by the P. destructans. Potter, who discovered the 

 organism, found that in white rot, an enzyme and a toxin were produced. 

 The former destroys the cell- walls of the plant, the latter is fatal to the 

 protoplasm. The enzyme is destroyed by boiling, which does not affect 

 the toxin. Application of this toxin to a diseased surface arrests the 

 disease by killing the bacteria. Soft black rot of cabbages is due to the 

 Bacillus oleracese Harrison. These bacteria are short and may occur 

 singly, in pairs, or in chains. They are motile and liquefy gelatin. This 

 organism differs only from the Pseudomonas destructans Potter in 

 possessing a number of peritrichous cilia, whereas the latter is possessed 

 only of a single polar flagellum. 



New Species of Thermophilic Bacilli.* — P. Georgevitch gives an 

 account of two new species obtained in hot springs at Yranje in Servia. 

 Bacillus thermophilus Yivoini is a short stout rod, which may occur 

 singly or in short chains. These organisms are at first motile, but lose 

 their power when granule-formation, preliminary to spore-formation, 

 takes place. These acid-fast granules appear also in the protoplasm, 

 before fission occurs. The bacillus grows upon ordinary media, the 

 optimum temperature being 43° C. Growth ceases at 50° C. A detailed 

 account of cell-division, spore-formation, and spore-germination is given. 

 B. thermophilus Losanitchi, from the sulphur springs at Vranje, grows 

 well upon agar to which a small quantity of a sulphur compound had 

 been added. It grows less freely upon ordinary media. Growth takes 

 place only between 45° and 78° C, the optimum point being 72 to 73° C. 

 Spores are formed in cultivation at 51° C., but developed in the greatest 

 numbers at the optimum temperature. This organism is a short bacillus 

 smaller than the foregoing, motile, and Gram-positive. Both organisms 

 are strict aerobes. 



Acid-fast and Granular Types of Tubercle Bacilli.f — Wehrli and 

 Knoll found in their investigations that a certain number of tubercle 

 bacilli were stained both by the Ziehl-Neelsen and by Much's modifica- 

 tion of Gram's method. A small number, however, could only be demon- 

 strated by the Ziehl-Neelsen process, while, on the other hand, about 

 50 p.c. of the bacilli were not acid-fast, but retained the stain with the 

 Gram-Much method. From this investigation it appears that the older 

 methods are insufficient for the identification of the tubercle bacillus. 



P. Wolff obtained somewhat similar results in his examination of 

 smears from the mesenteric glands of twenty-one children. In three 

 out of fifteen cases which afforded no clinical or histological evidences 

 of tuberculosis, he obtained Much's variety of bacillus. A guinea-pig 

 inoculated from a mesenteric gland of one of these cases yielded after 

 four weeks the typical acid-fast tubercle bacillus. Two of these three 

 children had given a negative v. Pirquet reaction. 



S. Rosenblat. in an investigation of sputum from eighty phthisical 



* Cemralbl. Bakt., 2te Abt., xxvii. (1910) pp. 150-1G7. 

 t Op. cit., lte Abt. Ref., xlvi. (1910) pp. 397-8. 



