306 MANUAL OF DETERMINATIVE BACTERIOLOGY 



2, 1888, 321; ? Pneumococcus Schmidlechner, Ztschr. f. Geburtshilfe u. Gynakol., 66, 

 1905, 291; not Pneumococcus Arloing, Compt. rend. Acad. Sci., Paris, 109, 1889, 430; 

 Mogallia Enderlein, Sitzb. Gesell. Naturf. Freunde, Berlin, 1917, 309.) From Greek 

 diploos, double; kokkos, a grain or berry; M. L., a sphere. 



Cells usually in pairs, sometimes in chains or more rarely in tetrads or small clumps. 

 Young cells Gram-positive. Parasites sometimes growing poorly or not at all on 

 artificial media. Fermentative powers usually high, most strains forming acid from 

 glucose, lactose, sucrose and inulin. The aerobic species are bile soluble while the 

 anaerobic species are not bile soluble. 



The relationships of the strictly anaerobic diplococci placed in this genus by Prevot 

 (Ann. Sci. Nat., S6r. Bot., 15, 1933, 140) to pneumococci are not yet entirely clear. 

 The anaerobic species are included here in the hope that this arrangement will stimu- 

 late research. 



The type species is Diplococcus pneumoniae Weichselbaum. 



Key to the species of genus Diplococcus. 



I. Aerobic, facultative. Bile soluble. 



1. Diplococcus pneumoniae. 

 II. Strictly anaerobic. Not bile soluble. 



A. Greater than 1 micron in diameter. 

 1. Carbohydrates not attacked. 



2. Diplococcus magnus. 



B. Not greater than 1 micron in diameter. 



1. Acid from glucose and lactose. 



a. Capsulated. Pathogenic. 



3. Diplococcus paleopneumoniae . 

 aa. Not capsulated. Non-pathogenic. 



4. Diplococcus plagarum-helli . 



2. Acid from glucose, not from lactose. 



a. Grows on ordinary culture media. Non-pathogenic. 



5. Diplococcus constellatus . 

 aa. No growth on ordinary culture media. Pathogenic. 



6. Diplococcus morbillorum. 



1. Diplococcus pneumoniae Weichsel- Trevisan, I generi e le specie delle 



baum. (Microbe septicemique du salive, Batteriacee, 1889, 34); Weichselbaum, 



Pasteur, Chamberland and Roux, Compt. Wiener med. Jahrb., 82, 1886, 485; Pneu- 



rend. Acad. Sci., Paris, 93, 1881, 159; moniemikrococcus or Pneumococcus, 



Micrococcus of rabbit septicemia. Stern- Frankel, Ztschr. f. klin. Medizin, 10, 



berg. National Board of Health Bull., 1886, 402; Bacillus septicus sputigenus 



Washington,:?, 1881, 781; Coccus lanceole, Fliigge, Die Mikroorganismen, 2 Aufi., 



Talamon, Communication a la Societe 1886, 262; Bacillus salivarius septicus 



anatom. de Paris, 58, 1883, 475; Micro- Biondi, Ztschr. f.Hyg.,£, 1887,195;DzpZo- 



coccus pyogenes tenuis Rosenbach, coccus lanceolatus sive capsulatus Foa and 



Mikroorganismen bei den Wundinfek- Bordoni-Uffreduzzi, Archivio per le Sci. 



tionskrankheiten des Menschen, 1884, 30 Med., 11, 1887, 387; Streptococcus 



(see Neumann, Cent. f. Bakt., 7, 1890, lanceolatus pasteuri Gamaleia, Ann. Inst. 



177); Micrococcus pasteuri Sternberg, Fsist., 2, 1SS8, ■i42; Streptococcus layiceo- 



Trans. Pathol. Soc. of Philadelphia, 12, latus Gamaleia, ibid., 443; Klebsiella 



1885, 162 (not Micrococcus pasteuri salivaris Trevisan, I generi e le specie 



