044: XOX-PATHOGENIC BACILLI. 



ture better at 37 C. Stains with the aniline colors and by Gram's method. 

 In gelatin stick cultures causes liquefaction of the gelatin; after some days 

 the upper portion of the liquefied gelatin has a pink color, while at the bot- 

 tom an abundant white sediment collects. Upon the surface of agar forms 

 a white layer which contains numerous spores. Liquefies blood serum ; in 

 this medium the bacilli are surrounded by a capsule, and are frequently seen 

 in long chains containing fifteen to twenty elements, all enclosed in a sin- 

 gle capsular envelope. Upon potato development is rapid at 37 C. ; at the 

 end of twenty -four hours a wine-colored layer is formed. Not pathogenic 

 for mice or guinea-pigs. Experiments made with pure cultures show that 

 it is pathogenic for bees and their Iarva3, and that it is the cause of an infec- 

 tious malady which is destructive to these insects in certain localities (in. 

 Italy). 



C. Nou-chromogenic, Non-liquefying Bacilli. 

 296. BACILLUS UBIQUITUS (Jordan). 



Found in sewage at Lawrence, Mass. ; also in water and in the air "ap- 

 parentlv abundant everywhere " ( ordan). 



Morphology. Bacilli from 1.1 to 2 /* long and about 1 ft broad reseinble 

 micrococci ; quite variable in f orm ; in bouillon short filaments are some- 

 times formed. 



Biological Characters. Aja.aSrobio andfacultativeanaerobic, non-lique- 

 fying, non-motile bacillus. Spore formation not observed. Grows at the room 



temperature in the usual culture media also at 

 37 C. Upon gelatin plates forms small, sphe- 

 rical or oval colonies, which have a yellowish 

 tins-e; at the end of two days the superficial 

 colonies are prominent, white, and glistening, 

 resembling a drop of milk ; they gradually in- 

 crease in diameter, become somewhat irregular 

 in outline, and acquire a dull brownish tint. 

 Under a low power the young colonies are seen 

 to be finely granular and to have a smooth con- 

 tour. In gelatin stick cultures development 

 occurs upon the surface and along the line of 

 puncture, producing a '' nail-shaped " growth 

 at the end of a week; the color is at first a 

 lustrous porcelain- white, which later changes 

 FIG. 215. - Bacillus ubiquitus. to a j^} brownish-gray ; grows well in slightly 

 x 1,000. From a photomicrograph. acid gelatin _ Upon the surface of agar a whit- 

 ish-gray layer is developed which has a slightly 

 metallic lustre. Upon potato a shining, white 



growth of limited extent. In milk coagulation occur-s quickly at 37 C., and 

 the milk acquires a strongly acid reaction. Reduces nitrates vigorously. 

 " This species apparently resembles quite closely the Bacillus candicans de- 

 scribed by the Franklands" (Zeit.fiir Hyg., Bd. vi., page 397). " It differs 

 from that, however, among other respects, in its capacity for reducing ni- 

 trates and in its mode of growth upon agar and potato " (Jordan). 



297. BACILLUS CAXDICANS (Fraiiklaiid). 



Found in the soil. 



Morphology. Short, thick bacilli, resembling micrococci ; often form 

 short filaments. 



Biological Characters. An aerobic, non-liquefying, non-motile bacillus. 

 Does not form spores. Grows slowly at the room temperature in the usual 

 culture media. Upon gelatin plates the superficial colonies resemble drops 

 of milk ; the deep colonies under a low power are seen to be spherical, slightly 



