540 



DESCRIPTION OF SPECIES. 



■Rods 1'2 to 1 '5 yu, in length, '6 to '8 m 

 in width. Colonies greyish-white, 

 viscid. 



The bacilli inoculated in the 

 depth of gelatine develop slightly 

 in the track of the needle, and pro- 

 duce a prominent grape-like growth 

 on the free surface. 



On potato the growth is grey or 

 tinged with yellow. 



They occur in water. 



Bacterium aerogenes (Miller). 

 — Short rods, singly and in pairs. 

 Motile. 



The colonies are circular, well 

 defined, and yellowish. 



Inoculated in the depth of gela- 

 tine the growth in the track of the 

 needle is brownish-yellow, and a 

 flat greyish button forms on the 

 free surface. 



On agar a pulpy layer develops. 



On potato the growth is pulpy 

 and yellowish-white. 



The bacteria possess great power 

 of resisting the effect of acids. 



They were isolated from the diges- 

 tive tract. 



Bacterium brunneum 

 (Schroter). — Motile rods, produ- 

 cing a brown colour. 



They were observed on a rotting 

 infusion of maize. 



Bacterium decalvans (Thin). — 

 Cocci, singly or in pairs, 1'6 fi in 

 length. 



They were observed in the roots 

 of the hair in cases of Alopecia 

 areata. 



Bacterium fasiforme (Warm- 

 ing). — Rods spindle-shaped, with 

 pointed ends, 25 fi long, and ■:> to 

 ■8 /x thick. They were described 

 as forming a spongy layer on the 

 surface of sea-water. 



Bacterium gingivae pyogenes 

 {Miller). — Short rods. 



The colonies are circular and 

 rapidly liquefy gelatine. 



The bacteria inoculated in the 

 depth of gelatine produce rapid 

 liquefaction in the track of the 

 needle and a white sediment. 



On agar they produce a moist 

 white growth. 



They are pyogenic when inocu- 

 lated subcutaneously in small ani- 



mals, and cause a fatal result when 

 injected to the peritoneal cavity. 



They occur in the deposit on the 

 teeth. 



Bacterium hyaointhi ( Wakker). 

 — Cocci resembling Bacterium 

 termo. 



They were observed in the yellow 

 slime of diseased hyacinth bulbs. 



Bacterium hydrosulfureum 

 ponticum (Zelinsky). — Long 



motile rods. 



On agar a dark cofPee-coloured 

 pigment is produced, which turns 

 black when exposed to air. 



Cultures give oflE sulphuretted 

 hydrogen. 



They were isolated from dredgings 

 in the Black Sea. 



Bacterium litoreum (Warming). 

 — Cocci ellipsoidal, 2 to 6 ft long, 

 1-2 to 2-4 jj, wide ; singly, never 

 as chains or zoogloea. 



They occur in sea-water. 



Bacterium luteum (List). — 

 Rods from I'l to Vi jj. long. Kon- 

 motile. The colonies are slimy, with 

 orange centres. 



Inoculated in the depth of 

 gelatine an orange growth occurs, 

 principally at the point of puncture. 



Milk is coagulated. 



They occur in water. 



Bacterium merismopedioides 

 (Zopf).— Threads 1 to 1-5 « in 

 thickness ; these subdivide into 

 long rods, short rods, and finally 

 into cocci. The cocci divide first 

 in one and subsequently in two 

 directions, forming characteristic 

 groups, which appear like merismo- 

 pedia. These groups may eventually 

 consist of 64 by 64 cells or more, 

 and ultimately form zooglcBa. The 

 cocci develop again into rods and 

 threads. 



They were observed in water 

 containing putrefying substances 

 (River Panke, Berlin). 



Bacterium navicula (Reinke 

 and Berthold). — Cocci spindle-form 

 or ellipsoidal, including motile and 

 non-motile forms. They have one 

 or more dark spots, which may be 

 coloured blue by iodine. 



They have been observed in rot- 

 ting potatoes. 



