i] MICROSCOPIC EXAMINATION 21 



8. Absolute alcohol, five minutes. 



9. Methylated spirit, five minutes. 



10. Stain specimens in selected dye. 



11. Wash in water. 



12. Wash in methylated spirit. 



13. Absolute alcohol. 



14. Oil of cloves. 



15. Xylol. 



16. Mount in xylol Canada-balsam. 



Demonstration offlagella. — Loffler [Centrabl. f. Bakt. und 

 Parasitenkunde, Bd. VI. Nos. 8, 9) has shown by a new 

 method that flagella of bacteria can be stained. Although 

 motile bacteria have been known or supposed to owe this 

 motility to the presence of flagella, these have in most cases 

 eluded demonstration, till Loffler by using a mordant of 

 tannin and ferrosulphate solution, previous to the stain, 

 showed with extreme clearness the actual presence of flagella 

 even in the weakest motile bacteria. Moreover, he showed 

 the quite unexpected and remarkable fact that while in 

 some only one flagellum at one end is present there are 

 others in which there are several such flagella, and even the 

 body of the bacteria may be completely invested in flagella 

 — e.g. in the case of the typhoid bacilli. Loffler's beautiful 

 photographs created deservedly great sensation amongst 

 bacteriologists, and a host of workers have devoted at once 

 careful attention to the subject, hence resulted several useful 

 modifications of the composition, reaction, and duration of 

 action of the mordant. We shall limit ourselves to the 

 single statement that by the flagella staining alone a 

 diagnostic differentiation between bacillus coli and bacillus 

 typhosus has become possible, the former possessing two to 

 eight, at any rate a limited number of flagella, whereas the 

 latter possesses quite a mass of wavy spirilla-like flagella ex- 



