adhere to that nomenclature in general use by the Ger- 

 man mycologists. 



Bacteria are distinguished in this system according to 

 form simply into (i) micrococci, or spherical bacteria ; (2) 

 oblong bacteria, or simply bacteria ; (3) bacilli, or rod bac- 

 teria ; (4) spirilla, or spiral bacteria. A disadvantage in 

 this nomenclature is the employment of the word bacte- 

 ria to designate two different conceptions the entire 

 tribe including all four classes, a general name, and the 

 second class oblong bacteria (Figs, i, 5), in distinction 

 from the others a double signification which has led to 



Fig. i. Various bacterial forms. i. Microcoocus septicus ; <z, scattered ; 

 ^, in chains torula. 2. Same in zoogkea form. 3. Bacterium termo. 4. Same 

 zooglcea. 5. Bact. lineola. 6. Bacillus subtilis. 7. Bacillus anthracis and blood- 

 corpuscles. 8. Bacillus (from mouth) with cilium. 9. Bacillus lepra. 10. Ba- 

 cilli with spores, u. Bacillus malariae. 12. Vibrio serpens. 13. Spirochaete 

 Obermeieri. 14. Spirillum volutans. 15. Sarcina. ^ 500. (Copied from Zieg- 

 ler's path. Anatomic, Jena, 1882.) 



some confusion. The micrococci are the smallest, and, 

 hence, individually least perfectly known ; so small, in- 

 deed, often less than one micromillimetre in diameter, that 

 nothing definite as to structure and contents has, as yet, 

 been ascertained. They seem to exhibit in general no in- 

 dependent motion ; they occur either isolated, in pairs, in 

 chains (streptococcus or torula), or, when multiplying 

 rapidly, in large numbers imbedded in a gelatinous mate- 



