EXPERIMENT STATION BULLETINS. 227 



T> mperature. — The optimum temperature is 25° (J.-30 C At 93° C. it remains alive 

 for 20 min., but is killed at 96°C lor the same time. Scarcely grows below 20°C. 



( 'oUmies. — They appear as little dark round spots at first, which send out from their 

 border filaments, lash like, and which grow through the solid gelatin without any 

 liquefaction. After increasing in size they liquefy quite rapidly, but the colony does 

 not change in general appearances. 



Gelatin tube-cultures. — The growth is along the entire line of inoculation, growing 

 better at the surface than deep in the tube. After the growth has become quite 

 heavy along the line of inoculation a number of short stubby processes are given off 

 and the entire growth resembles a pine tree with its limbs cut off six inches from the 

 trunk. Developing still further, the gelatin begins to liquefy and there is a long 

 narrow funnel produced. 



Agar inclined tube-cultures. — There is a spreading, raised, wrinkled growth over the 

 surface. The borders are irregular and somewhat crystalline. 



Bouillon cultures. — There is a heavy growth, most of which settles in the bottom. 

 Some masses are left suspended in the liquid and the bouillon does not clear readily. 



Milk cultures. — The casein is curdled, then peptonized completely and the liquid is 

 dark in color. 



Potato tube-cultures. — A grayish white mealy growth spreads over the surface of the 

 potato. 



Blood serum cultures. — Serum is completely peptonized. 



Growth. — Comparatively slow. 



Pigment. — None. 



Oxygen conditions. — Grows better in presence of oxygen, but will grow without it. 



Odor. — No characteristic odor. 



Acids. — Acid is produced in presence of lactose but not without it. 



Beiiavior to gelatin. — Liquefies gelatin. 



No. 112. 



Source.— Taken from changed Pasteurized milk G. 



Form and grouping. — Bacillus. Its thickness varies from 1 m to H m and its length 

 4 m to 12 m. The bacilli are found single and in short threads. 



Spores. — Median spores are formed in old cultures on agar. 



Protoplasm and cell-wall. — The protoplasm is somewhat granular and the cell-wall 

 shows distinct markings between the cells when formed in threads. 



Motion. — Sluggish and serpentine. 



Staining reaction. — Stains readily with the ordinarv aniline stains. 



Temperature. — It grows best at 26° C.-30 C. Below 15° C there is no growth at 

 all. 70° C. for one hour does not kill it but 75° C. for 20 min. does. 



Colonies. — The center of the colony is dark and without definition, appearing as if 

 made up of a bunch of threads. Its border is ill defined and from it proceed many 

 tine filaments and some heavy lash-like processes. At times the lash-like processes 

 resemble a string of beads. 



Gelatin tube-cultures. — There is only a small growth deep in the tube along the line 

 of inoculation; at the surface a shallow cup soon forms from liquefaction and this 

 continues to deepen and widen until a long wide funnel is made and eventually all 

 the gelatin is liquefied. 



Agar inclined tube-cidtures. — Along the streak forms a series of oval colonies; those 

 at the bottom of the streak are much larger than those at the top. The growth is 

 moist and grayish white. 



Bouillon cultures. — Little patches of granular growth are found on the surface. The 

 cloudiness appears granular and is very persistent, only a slight sediment forming 

 on the bottom. 



Milk cultures. — The milk loppers and acts much like ordinary souring. 



Blood serum cultures. — Heavy white growth on the surface, but it is not peptonized. 



Growth. — Rapid. 



Pigment. — Non e. 



Oxygen conditions. — Requires oxygen for its development. 



Odor. — No odor. 



Acids. — Acid is produced in the presence of lactose, but in its absence there is 

 none formed. 



Behavior to gelatin. — Liquefies readily. 



