36 STORRS AGRICULTURAL EXPERIMENT STATION. 
The two following groups, III. and IV., are separated from 
each other by the color of a pigment which they produce, the one © 
giving a demon yellow and the other an orange yellow pigment. 
It has been found by experience that brownish colors, especi- 
ally upon potato, have no significance, but that lemon and 
orange yellow colors are quite distinct from each other, and ; 
may be used to characterize different groups. Occasionally 
forms may be found in which it is a little difficult to determine 
to which of these two groups they belong. For convenience — 
in classification some of these forms have been included under — 
both groups, but as a rule the yellow and orange are sharply — 
separated. q 
GROUP II]. CHROMOGENIC TYPE. (ORANGE.) 
No. 199. Sarcina flava. 
This species has been occasionally found in milk. 
No. 188. J. aureus lactis. (n. sp.) 
Morphology, a coccus, size, .8u4, in pairs or in clumps. 
Gelatin plate; a round, opaque colony, surrounded by a halo which is uni- 
formly granular, somewhat indented and cracked. This increases to a large, 
uniformly granular liquid zone, which spreads in all directions. The lique- 
faction at first is chiefly below the surface. 
Gelatin stab; a shallow pit is produced, which deepens into a horizontal layer ~ 
with a yellow sedimentand slightly cloudy liquid. Liquefaction becomes complete. 
Agar and potato; an abundant, moist, glistening Naples yellow growth. 
Milk; after three weeks becomes curdled and rendered alkaline. Later is par- 
tially digested into a transparent liquid, with considerable undigested sediment. 
No. 108. (Quite common.) 2. aureus minutissimus. (n. sp.) 
Morphology; a bacillus, size, .4u by 1.64. Three or four may be united 
together, and in bouillon, long tangled threads. ; 
Gelatin plate; surface colony at first thin, irregular, branching and creeping. 
The deeper colonies are burr ike, with a yellow center and radiating processes. 
After two days a liquefying pit is formed, with a yellow center and irregular 7 
processes extending into the gelatin. The whole is quite characteristic. 
Gelatin stab; a deep, narrow funnel, with a brilliant yellow sediment and — 
scum, and a somewhat cloudy liquid. 4 
Agar, an orange yellow growth, spreading over the whole surface. 
Potato; a dark orange growth of a very deep color and striking appearance, 
Bourllon,; a slight scum on a uniformly cloudy liquid, and a yellow sediment 
collects after some weeks. 
Milk, at 20° becomes somewhat pasty and dark colored. Slightly slimy, 
and is alkaline in reaction. Butter made from cream ripened with this organ-_ 
ism develops an aroma of decay which is unpleasant. No very decided flavor. 

