50 HISTOEICAI. NOTES ON BEE DISEASES. 



appearance of seaweed. This appearance is distinctively characteristic; and as the 

 growth is very rapid, this method commends itself for making a quick diagnosis of the 

 presence of the bacillus in larvae supposed to be diseased. 



Morphology. — A slender bacillus with slightly pointed but rounded 

 ends. They usually occur singly, but may form chains of various 

 lengths. This species possesses a single flagellum at a pole. No 

 capsule has been demonstrated. 



Spores. — The spores are about 2 /i in length and 1 ;« in breadth. 

 Under favorable conditions they begin to germinate in about three 

 hours. 



Motility. — They are actively motile, especially in fresh#cultures. 



Oxygen requirements. — Harrison agrees with Cheyne (p. 31). 



Bouillon. — In 14 hours at 37° C. there is a slight cloudiness, in 24 

 hours the culture is turbid, and in 48 hours the turbidity is further 

 increased and a pellicle begins to form. After 96 hours the broth is 

 rather clear, with a white, rather massive, and somewhat tenacious 

 pellicle. Reaction of the medium after 10 days has changed from 

 + 0.08 to the neutral point. 



Glucose. — Growth heavier in this medium than in plain bouillon. 

 Reaction in 10 days is acid, having changed from +2 to +4.6, 

 Involution forms may occur. They are slightly curved and average 

 5 /i in length. 



Lactose. — The growth resembles that in plain bouillon, but is 

 slightly heavier. Acid is produced but less in quantity than in 

 glucose. 



Saccharose. — Turbidity is greater than in smy other bouillon and 

 more acid is produced. 



Potato. — Harrison writes: 



On potatoes the growth differs considerably, according to the reaction and age of 

 the potato. Sometimes a brownish wrinkled growth forms, which gives off a peculiar 

 odor; at other times a dryish yellow layer appears. 



Milk. — At 37° C. coagulation of the casein occurs in three days. 

 The medium becomes yellomsh in color and gives off a pecuhar odor. 

 The coagulum finally digests, leaving a whejdike fluid. 



Blood serum. — Growth takes place slowly. Many long filaments 

 are common, which may be wavy and which may vary in thickness. 

 The serum is liquefied. 



Gelatin tubes. — On the surface in three days there occurs a ramifying 

 growth. In five days the entire surface is liquefied. A whitish 

 growth takes place along the line of puncture, from which numerous 

 shoots branch out in the gelatin in all directions. This gives a hazi- 

 ness to the medium, which now begins to liquefy. 



In the description which Harrison made he quotes rather freely 

 from Cheyne. Some of his statements suggest that at least part of 

 the time he was working with other species than BaciUus alvei. 



