■APPENDIX. 425 



(4) Bienstock's putrefactive bacillus {B. Futrifciii Colt, "Drumstick" 

 bacillus).— "fias first separated from feces. On gelatine it has first 

 a peculiar opalescent appearance, but later it becomes yellowish ; on 

 agar-agar it has much the same appearances ; is an extremely motile 

 organism, which occurs in longer or shorter threads ; usually the long 

 threads break up into shorter rods, about 3a« in length, at one end of 

 which may be seen a spore similar to that described in the tetanus bacillus ; 

 this terminal spore giving to the bacillus the characteristic drum -stick shape. 



(5) Bacillus or kftothrix epidermidis. — Occurs in the fragments of 

 epidermis taken from between the toes ; grows very sparsely on gelatine 

 and on agar-agar, where it forms only a superficial growth ; on potatoes, at 

 a temperature of 15 to 20°C.,it occurs in the form of transparent fluid drops, 

 which gradually run together, become thicker, and form a characteristic 

 superficial skin ; also forms a similar skin on blood serum ; is a bacillus of 

 about 2.8 to 3/i in length, and .3/1 in diameter ; forms spores from 1.2 to 

 i.5fi in length, and .3 to .4^1 in breadth ; this spore formation goes on best 

 at a temperature of 25° C. 



c. Colonies form white nail-head projections on plates, and on the surface 

 of tube cultures, 

 a. Colonies microscopical with a granular border. 

 j3. Colonies with smooth borders, see p. 426. 



a. Colonies microscopical with a granular border. 



(1) Bacillus pneumonia (Friedlander). — Found in the lung and in the 

 rusty-coloured sputum of croupous pneumonia. Occurs in plates as small, 

 round, well-defined, darkish yellow or olive green granular colonies in the 

 deeper layers of the gelatine ; on the surface appears as white, thick, well- 

 defined projectingpoints ; in the gelatine needlecultures the growth has the cha- 

 racteristic nail {with rounded head) appearance, the superficial growth almost 

 appearing like a very white, split, porcelain bead, that has been dropped 

 on the surface (after a time there is usually slight coloration of the gelatine, 

 and small bubbles of gas are formed if the gelatine is not too solid) ; grows 

 best at a temperature of from 16° to 43° C. ; at the higher temperature (on 

 potatoes) it forms a moist, yellow mass, in which little bubbles of gas may 

 be seen ; grows very rapidly, and is not strictly a;robic. Under the micro- 

 scope seen as short, thick bacilli, with rounded ends, or oval cocci, which 

 are frequently arranged in pairs. When found in the lung tissue or sputum 

 it is usually surrounded by a delicate capsule, which gives it a very 

 characteristic appearance ; but this capsule is not, as a rule, found in 

 cultures. The organism is non-motile ; sometimes gives rise to pneumonia 

 in mice, guinea-pigs, and dogs, but does not affect rabbits. No spores 

 have been demonstrated. 



(2) Bacillus crassus sputigenus. — Found in the sputum and in the " fur " 

 scraped from the tongue. Forms on gelatine plates greyish-white viscid 

 drops, which project above the surface of the gelatine ; colonies seen with 

 a lens are greyish brown, coarsely granular, and have a somewhat irregular 

 margin ; in needle cultures have the same characteristic nail appearance as 

 No. I, and on potatoes also grow like No. I ; short, thick rods, with 

 slightly rounded ends, sometimes described as being like bent sausages ; 

 said to form spores at a temperature of about 35° C. Kills mice in about 48 

 hours, and in larger doses may kill rabbits and dogs in a very short time. 



