Ethel M. Duidge 57 



long as the rods. No capsules have been observed. Involution forms 

 are produced in 24 hours in nutrient broth at 30° C. and in old cultures ; 

 these take the form of long threads up to lOO/z long and irregularly 

 swollen. 



It stains well with all the usual stains, especially with Gentian violet 

 and is Gram-positive. 



Cultural Characters. 



Nutrient agar colonies. At 18° — 20° C. the colonies are visible to 

 the naked eye in 48 hours ; in three days the surface colonies are -5 to 

 3 mm. in diameter, round-irregular, glistening and translucent ; in four 

 days they are up to 5 mm. in diameter, of a light coppery tint by trans- 

 mitted light, creamy white by reflected light. Some of the colonies 

 are inclined to spread and become lobulate, but the majority are more 

 or less circular, with a smooth margin. 



The submerged colonies are at first punctiform, afterwards lenticular. 

 There are a few crystals in old cultures. 



Nutrient agar streak. Cultures form a flat, w^hitish glistening growth, 

 spreading out at the base of the slant; very old streaks are slightly 

 fluorescent. 



Nutrient agar stab. The best growth is at the top. 



Nutrient gelatine colonies. Visible in 48 hours ; the submerged 

 colonies are minute white points ; those on the surface slightly larger, 

 with an undulate margin around which there is a slight indication of 

 liquefaction. After four days the surface colonies are sunk in small 

 craters of liquefied gelatine, they are moist and glistening semi-trans- 

 parent, often with a small white nucleus in the centre, surrounded by 

 several concentric rings of whitish, granular matter. Liquefaction of 

 the gelatine is complete in 8 — 10 days. 



Nutrient gelatine stab. In three days at 18 — 20° C. there is a small 

 crater of liquefaction 4 — 8 mm. broad and 8 — 10 mm. deep, and the 

 surface growth has sunk to the bottom of the crater; in seven days 

 the liquefaction involves the whole thickness of the tube and becomes 

 stratiform. 



Potato. On this medium there is a raised, creamy-white grow^th with 

 smooth edges along the needle track. 



Turnif. No growth. 



Carrot. The growth on carrot is very scanty, thin, and spreading. 



Parsnip. A very much raised, shining streak develops, standing 



