346 MICROBIOLOGY 



at first, but after 3 or 4 days a milky growth is observed which 

 increases until a luxuriant growth is formed. It varies from 

 lemon-yellow to a gray in color. In old cultures it has a 

 brown color. 



Serum. A slightly raised growth which is confined quite 

 closely to the line of inoculation appears on the surface of 

 solidified serum. 



Bouillon. The medium becomes uniformly clouded in 24 

 hours; later it shows a tendency to clear by a settling of the 

 organisms. A somewhat viscid sediment is thus formed in the 

 bottom of the tube. In older cultures a slightly grayish band 

 of growth adheres to the glass at the surface of the medium. 

 The acidity is at first slightly increased, and a pellicle is 

 sometimes formed. In bouillon containing lactose, dextrose 

 and saccharose, the acidity is slightly increased but gas is not 

 produced. 



Milk. The acidity is increased. Coagulation usually 

 takes place after the third day. 



Life conditions and properties B. alvei is a facultative 

 anaerobe. Old cultures give a strong indol reaction. 



Resistance. It is destroyed in the vegetative form with 

 a 3% solution of carbolic acid and 1 to 2000 solution of bi- 

 chloride of mercury in three minutes. A solution of bichloride 

 of mercury 1-1000 kills the spores after 30 minuutes' exposure. 



Pathogenesis. It is pathogenic for young honey bees. 



BACILLUS LARVAE WHITE. 



Synonyms. Bacillus of American foul brood ; Bacillus X 

 White. 1 



Place in nature. This organism was discovered by White 

 in the study of a bee disease now known as American foul 

 brood. Its distribution seems to be similar to B. alvei. 



Morphology. It is a slender rod, having a tendency to 

 form in chains. This is especially true when grown in bee- 

 larvae bouillon. It is rather sluggishly motile. Spore forma- 



White. Report N. Y. State Dept. of Agric., Jan. 1904. 



