BACTERIA OF THE INTESTINE. 19 



Bee No. 13, 2.000 or more gray colonies. 



Bee No. 14, j^east colonies and a few colonies of bacteria showing ground- 

 glass appearance. 



Bee No. 15, 2,000 or more colon-like colonies (B. cloacd-). 



The following are the species which have been found to be most 

 constant. The reader is referred also to the description of the yeast 

 plant found very frequently in the intestine of the normal honey bee, 

 described under " Saccharomyces and fungi." 



Bacterium D. 



OcGurrence. — Frequent in the intestine of the healthy honey bee. 



Agar colony. — Deep colonies when magnified are coarsely granular, showing a 

 dark brown center, with a thin and ill-defined border. 



Morphology. — A in-eparation made from a young culture taken from a glu- 

 cose fermentation tube shows rods with rounded ends, occurring singly and in 

 pairs, staining easily and uniformly with carbol-fuchsin, and measuring O.T^a to 

 l.Syti in length and O.Syu. to 0.7/i in thickness. 



Motility. — No motility could be observed. 



Spores. — No spores could be demonstrated in young cultures. In old cultures 

 their presence is questionable. 



Oxygen requirements. — Strictly anaerobic. 



Bouillon. — In straight tubes no growth occurs. 



Glucose. — A moderate cloudiness can be seen in the closed arm. while the 

 open bulb remains clear. No gas is produced. Reaction about neutral. 



Glucose agar (Liborius's method). — Growth is rather slow. After 3 days a 

 moderate growth may be observed ; later, if cultures have recently been iso- 

 lated from the bee's intestine, the growth imparts to the medium a diffused 

 hazine.ss or cloudiness. After many generations the culture loses this property. 



Glucose gelatin (Liborius's method). — Very slow growth occurs in the depth 

 of the medium. No liquefaction takes place. 



Bacillus cloacae. 



Occurrence. — Found in the intestine of a large number of healthy honey bees. 



Gelatin colonies. — Superficial colonies are thin and blue to gray in color; deep 

 colonies, brown, regular, granular, and s])heri(al to lenticular. 



Agar colonies. — Superficial colonies are partially opaque, brown, finely granu- 

 lar, with well-defined margin ; deep colonies are regular, spherical, or lenticular, 

 with well-defined margin. 



Morphology. — The rods from 2-t-hour agar cultures have rounded ends, vary- 

 ing in length from Ifi to 2/i and in width from *\7/x to o.9/x. They are usually 

 found singly or in pairs. Involution forms are not uncommon. With carbol- 

 fuchsin they stain uniformly. This species possesses a few peritrichic flagella. 



Motility. — Active motility is observed in young cultures. 



Spores. — No spores are formed. 



Gram's stain. — The bacillus does not take Gram's stain. 



Oxygen requirements. — Facultatively anaerobic. 



Bouillon. — A uniform cloudiness appears in 24 hours. Growth continues until 

 the medium becomes heavily clouded, followed by a gradual settling of many of 

 the organisms, forming a viscid grayish-w'hite sediment. A gray friable mem- 

 brane, which adheres to the sides of the tube at the surface of the medium, is 

 sometimes produced. Upon agitation this membrane breaks up and sinks to the 



