16 GENERAL SYSTEMATIC BACTERIOLOGY 



were divided into two groups "Organis externis nullis" and "Organis 

 externis.'" The forms now included among the bacteria were all to 

 be found in the ten genera of the first group. These were separated 

 as follows (p. XXVI) : 



Mueller's Classification of Protozoa, etc. (1786) 



Crassiuscula 



1. Monas: Punctiforme 



2. Proteus: Mutabile 



3. Volvox: Sphaericum 



4. Enchelis: Cylindraceum 



5. Vibrio: Elongatum 

 Membranacea 



6. Cyclidium: Ovale 



7. Paramoecium: Oblongum 



8. Kolpoda: Simatum 



9. Gonium: Angulatum 

 10. Bursaria: Cavum 



Two of these genera contained organisms now included among the 

 bacteria. In the genus Monas were ten species and in Vibrio thirty- 

 one species. Of these very probably Monas termo, M. punctum and 

 M. lens, Vibrio lineola, V. rugula, V. bacillus, V. undula, V. serpens 

 and V. spirillum were bacteria. The monads were spherical or ovoid 

 in shape, the vibriones longer, and in most species spiral. 



Within the next two decades, no advance was made in the classi- 

 fication of the forms now known as bacteria. However, three generic 

 names were created by as many writers for organisms supposed to be 

 fungi, but which many decades later were shown to be bacteria. 

 The first of these was named by Link (1795), who described Polyan- 

 gium vitellinum, an organism in its fruiting stages bearing a close resem- 

 blance to a mold, but which was later shown by Thaxter (1892) to 

 belong to the Myxobacteriaceae. The second name was applied to the 

 species Sefmtia marcescens by Bizio (1823) . This investigator had under- 

 taken to study the cause of an outbreak of "bloody " polenta which was 

 causing much superstitious fear among the peoples of northern Italy. 

 He attributed the difficulty to a fungus which developed a red pigment 

 on farinaceous foods. This was probably the organism now more com- 

 monly termed Bacillus prodigiosus. Somewhat later Sette (1824, 

 p. 51) named what is apparently the same organism Zaogalactina ime- 

 tropha, also regarding it as one of the fungi. 



