374 GENERAL SYSTEMATIC BACTERIOLOGY 



with colorless or light colored cells, Vvithout motility, remaining after 

 cell division united into rosary-like threads, many celled families or 

 slimy masses. The first organism to which the name was given was 

 Micrococcus 'prodigiosus (Ehr.) Cohn. This organism is now generally 

 removed from this genus, because of its shape. The next organism 

 named was M. luteus (Schroet) Cohn. This form may well be con- 

 sidered the type of the genus as it has been adequately described. 



The name Micrococcos was used by Billroth (1874, p. 6) to designate 

 a growth form of his pleomorphic Coccobacteria septica, in which the 

 cells consisted of very minute spheres. He did not use the name in 

 a generic sense. In 1875 Cohn split his former genus into two, creating 

 the new genus Streptococcus. His revised definition of Micrococcus 

 included those organisms with spherical cells, united into glairy families 

 amorphous, cells without phycochrome, very small, Trevisan (1879 

 p. 126) gives the following generic description: 



Micrococcus Hallier em. Cohn. (Zoogalactina Sette 1824; Serratia Bizio 1827; 

 Microzyvia Bechamp 1868; Microsporon Klebs 1872; Microsphaera Cohn 1872). 

 Cellulae globosae vel globoso-ovoideae. Multiplicatio divisione cellularum vege- 

 tativa in omnes directiones. 



It was included under Euhacterieae. In all, sixteen species were listed, 

 many of them forms now included among the rod-shaped organisms. 

 Among forms listed which may be included among the true cocci are 

 M. luteus, M. lactis, M. septicus. Luerssen (1879, p. 171) followed the 

 original description of Cohn, as did also Magnin, (1880, p. 72). The 

 latter divided the genus into three groups of species. Micrococci 

 chromogenes, M. zymogenes and M. pathogenes Winter (1880, p. 42) 

 gave the following generic diagnosis: 



Zellen farblos oder blass geffirbt, kugelig odereiformig-elliptisch, unbeweglich, 

 nur in einer Richtung sich theilend. Die Tochterzellen trennen sich entweder 

 bald von einander, oder bleiben zu zwei oder mehr kettenartig verbunden, oder 

 bilden Zoogloea. Sporenbildung nicht sicher bekannt. 



Was ich oben iiber die Unterscheidung der Aden gesagt habe, gilt ganz beson- 

 ders von Micrococcus. Die angenommen Arten zeigen in Gestalt und Grosse 

 keine oder sehr geringe Unterschiede und es bleibt uns nur die chemiscge Thatig- 

 keit als Mittel zur Auseinanderhaltung der Arten, die daher etwas ausfiirlicher 

 behandelt worden ist. 



Ogston (1883, p. 27) used the name Micrococcus, but without species 

 designation. He included the chain forms (streptococci) as well as a 

 new type which he termed staphylococci. Van Tieghem (1884), 

 and Grove (1884, p. 6) all followed Cohn more or less closely, though 



