58 LABORATORY BACTERIOLOGY 



EXERCISE XVI 



THE MORPHOLOGY OF BACILLUS 



86. The bacilli which are to be studied in this exercise 

 exhibit in addition to the rod-shaped bodies the essential mor- 

 phological variations of this genus, viz. number of fiagella 

 and spores. The two latter are held in common with the 

 bacterium. The staining of the organs of locomotion (fiagella) 

 and the spores will be taken up in separate exercises. 



87. Work for this exercise. Carefully examine and study 

 the cultures made in Exercise XV, following the directions 

 given for the examination of cultures and preparations in that 

 exercise. 



Measure carefully with the filar micrometer the length and 

 thickness of 8 individual bacteria in one of the stained prepa- 

 rations. Record the measurements in microns (written /i). 

 (For the use of the micrometer, see Appendix, also chapter 

 on magnification and micrometry in The Microscope, by Pro- 

 fessor S. H. Gage.) 



State fully in the notes the generic characters of the genus 

 Bacillus. 



Inoculate a tube of bouillon and one of agar from each of 

 the cultures (which will be furnished) of a Bacterium and of 

 a Spirillum. 



Inoculate a tube of agar with B. subtilis for Exercise XVIII. 



