214 



LABORATORY EXERCISES IN BACTERIOLOGY. 



the globular and short rod forms, is devoid of appendages; but frequently in the longer 

 rods, both straight and curved, and occasionally in the former, there are to be found 

 delicate hair-like or lash-like extensions known as flagella, regarded as the means of 

 active movement. These flagella are to be seen after the application of special methods 

 of staining, best in young cultures grown upon solid media; and are by no means con- 

 stantly demonstrable even in the same variety or in all forms of motile bacteria by the 

 methods at present employed. However, they are sufficiently 

 constant to be of service in classification and identification 

 (Migula). When such flagellum is single upon the cell, flagella- 

 tion is said to be monotrichous ; when numerous at one or both 

 poles of the cell, it is spoken of as lophotrichous (flagella polar) ; 

 when single at each pole, amphitrichous ; when found all along 

 the sides as well as at the ends the flagellation is said to be peri- 

 trichous. In the adopted classification coccus forms possessed 



of flagella are termed planococci (sing., planococcus) ; flagellated sarcinae, as plano- 

 sarcince (sing., planosarcina) ; a straight, rod-shaped organism with polar flagella, as 

 a pseudomonas (pi., pseudomonades or pseudomonads) ; straight rods with peritrichous 

 flagella, as bacilli; straight rods devoid of flagella, as bacteria; comma-shaped rods 



FIG. 62. TYPES OF 

 CAPSULE BAC- 

 TERIA. 



D 



FIG. 63. FLAGELLATION OF BACTERIA. 

 A. Planococci. B. Pseudomonads. C. Bacilli. D. Microspine. E. Spirilla. 



with one or two lophotrichous flagella, as microspirce (sing., microspira) ; comma- 

 shaped rods without flagella, as spirosomata (sing., spirosoma) ; the term spirillum 

 is retained for those comma-shaped rods which have a bunch of flagella at one or 

 both poles (Fig. 63). 



Exercise 48. Staining of Supposed Nuclear Granules. Make film 

 from known culture of Bacillus coli in ordinary manner; but in fixing pass 

 through the flame ten times instead of two or three. Stain four or five 

 minutes with Loefrler's solution, boiling, replacing the solution on the film 

 as it evaporates. Wash well with water and dry. Examine in oil without 

 cover. 



Exercise 49. Staining capsules (Johne). Prepare a film of sputum 

 from a case of acute pneumonia, as before described for sputum from a 

 tuberculous case. Cover preparation with two per cent, aqueous solution 



