EXPERIMENT STATION BULLETINS. 219 



Temperature. — Its optimum temperature is 28° C. Scarcely grows at 15° C. Lives 

 at a temperature of 96° C. for 20 min., but is killed at 100° C. for the same time. 



( Monies. — The center before liquefaction occurs is bright and glistening and of a 

 very light color, almost translucent. However, it soon becomes liquefied. In the 

 liquid portions are observed small patches of thick masses of bacteria floating about 

 from one place to another. From the cireulan border radiate line liber-like processes 

 which are quite uniform in length and resemble the ray crown. 



G( latin tube-cultures. — At first there is a slight growth along the line of inoculation. 

 After a few hours longer, a funnel-shape liquefaction occurs only at the surface, and 

 this gradually extends across the tube until the upper portion of the tube is liquefied 

 and the lower portion entire. About this time a s -urn forms on the surface. Having 

 reached this point in its stage of development, its progress is not rapid and the 

 remaining gelatin in the tube is very slow in liquefying. 



Agar inclined tube-culture. — A dry spreading growth adhering closely to the agar in 

 a scum-like sheath. Along the streak the growth is much heavier. 



Bouillon culture. — Wrinkled dark scum on surface, beneath which the liquid is 

 clear. No sediment forms at the bottom. 



Milk cultures.— Milk is at first curdled then peptonized, eventually becomes clear 

 but quite dark. 



Potato tube-culture*. — Spreading dirty white growth over surface of potato. It 

 gradually becomes a creamy-white and when it grows old is wrinkled and mealy. 



JHhml si rum tubes. — Serum is peptonized only slightly underneath the growth, which 

 is creamy white. 



Growth.— Very rapid. 



Pigment. — None. 



Oxygi u conditions. — Grows best in oxygen, very slightly anaerobically. 



Odor. — None perceptible. 



Acids.— No add produced even in presence of carbohydrates. Lactose had no 

 influence in changing this condition. 



Behavior /" gelatin. — Liquefies gelatine readily. 



Gas production. — No gas observed in any of the cultures, not even in presence of 

 carbohydrates. 



No. 9. 



Source. — Pasteurized milk not recorded in this bulletin: also samples B and C. 



Form oud grouping. — Its thickness is 1 m to 1} m. and its length varies from 3 m to 

 9 m. Ends are slightly rounded. Forms in long threads, short threads and single. 



Spores. — It produces median spores. 



Protoplasm. — Homogeneous until the formation of spores at which time it becomes 

 markedly granular. 



Motion. — It has a slow progressive and serpentine movement. 



Staining reaction. — Stains readily with ordinary aniline stains. 



Temperature.— Not killed at 90 J C. for 20 min., but killed at 93° C. for 20 min. 

 Scarcely grows at 15° C. Optirnmn temperature is about 30° ( '. 



Colonies. — At first the colony appeai-s light and crystalline, afterward becoming 

 much darker. Soon after developing it begins to liquefy the surrounding gelatin. 

 From its border is a radiating mass of fine and straight processes but this appear- 

 ance may be almost completely lost in further liquefaction. The contents of the 

 body as soon as liquefaction begins assume no definite arrangement: patches consist- 

 ing of masses of bacteria may be seen floating about in the peptonized gelatin. 

 While the above is the usual course of development, the colony may in the early 

 stage of its development resemble a composit flower and again may form in concen- 

 tric rings of different shades and density. 



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

 as soon as the growth is visible, liquefaction begins and extends to the end of the 

 puncture, liquefying as fast at the bottom of the puncture as at the top. In this way 

 the gelatin is liquefied very rapidly. There is no clearing after liquefaction, the 

 suspended material of a flocculent nature remains as when first formed. The scum 

 which forms on the surface, however, falls eventually to the bottom. 



Agar inclined tube-cultures. — It usually spreads over the entire surface in a moist and 

 uniform mass of a creamy white consistency. As the culture becomes old, it dries 

 down in wrinkles. 



Bouillon cultures. — Scum forms on top. It is thin and falls to the bottom after a 

 few days. The body of the bouillon remains cloudy and does not become clear. 



