CLASSIFICATION OF DAIRY BACTERIA. I41 
Variety A.—This variety, also found in milk in Middletown, agrees with 
the above in most respects, differing in the following points: Size, 34x 1.5m. 
Spores are produced. The gelatine forms a pit full of threads. Milk is curdled 
and after digestion shows a clear liquid and tenacious scum. The potato 
growth is wrinkled. , 
Variety B.—This organism forms no chains nor spores. Its colony is lemon. 
yeilow, even when viewed under the microscope, a very unusual character; later 
it liquefies and sends processes into the gelatine. Its gelatine stab is infundib- 
uliform, or a dry pit. Its growth on agar is lemon-yellow and very thin. 
It is doubtful whether these three varieties should be grouped together, and 
certainly they should not if it is true that two of them do not form spores. We 
have lost these cultures and are unable to verify the characters above given. 
Therefore we insert them in their original form. 
Bact. lactis minutissimum., A very slender, orange Bacterium, We have 
not fouud this since the original description in 1899. The following are the 
characters as then described. 
Morphology.—Size, 1.5@x.4¢. Forming long chains, and not producing 
spores, 
Gelatine colony.—Surface colony irregulary branching; ‘deep colonies burr- 
like, with a yellow centre and irregular processes, or sometimes simply lobed. 
Rays extend from a liquefying pit into the gelatine. 
Gelatine stab,—Begins to liquefy in two days with an infundibuliform or crati- 
form liquefaction, and a brilliant yellow sediment. 
Agar streak.—A luxuriant, widely spreading, orange growth, covering the 
whole surface. 
Bouillon.—A sediment, turbidity and a pellicle. 
Milk,—Rendered alkaline and becomes somewhat thick and dark colored, but 
no visible digestion. 
Potato.—Luxuriant, deeply orange. 
Grows better at 20° than at 37°. Aerobic. 
Variety A.—A second culture, found later, may be a variety of the same, 
although it is‘not so small. It is .6% in diameter, and does not appear to form 
chains. Its colony is brilliant yellow, smooth and translucent, but does not 
show the irregular processes. Milk does not become thick. The color on 
potato is bright yellow rather than orange. 
Bact. lactis Marshalli u.>. A slimy milk, yellow Bacterium. This is the 
organism with which Marshall has worked and which was shown by him to 
have a hastening action upon lactis bacteria (Cent. f. Bact. II.). The follow- 
ing characters were determined by us from cultures sent by him, and agree 
_essentially with those determined by him: 
Morphology.—A rod, not forming chains. Size, 1.24x.3u. (Marshall’s 
measurements, I.7#-5.25 x .8u-.875u4.) It produces no spores, has no capsules 
and Gram stain is negative. 
