506 MICRO-ORGANISMS IN WATER 



SAECINA LUTEA 



|TiQUEFIES GELATINE | 



Authority. Schroeter, ' Ueber einige durch Bacterien gebildete Pigmente, 

 Beitrage z. Biologic der Pflanzen, vol. i., Heft ii., in note at foot of p. 119 ; 

 also ' Studies on some new Micro-organisms obtained from Air,' Percy 

 Frankland, Phil. Trans. Roy. Soc., vol. clxxviii., 1887, p. 265. 



Where Found. Originally by Schroeter on potatoes exposed to the air. 

 Found also in water by Tils (loc. cit.). Found in the conjunctival sac of the 

 eye by A. E. Fick, Ueber Microorganismen im Conjunctival Sack, Wiesbaden, 

 1887, p. 48. 



Microscopic Appearance. Very large cocci from 1-5 to 2-5 ^uin diameter, and 

 arranged in twos and fours, and in the three dimensions -of space. They stain 

 easily with very weak solutions of methyl violet, and are not decolourised when 

 subsequently treated by Gram's method (Fick). The arrangement in cubical 

 packets is especially well seen in drop-cultures. It is not motile. 



Cultures. 



GELATINE PLATES. Grows very slowly, producing small, round, yellowish 

 colonies. Under a low power the centre of the colony is of a dark greyish 

 green colour ; it is finely granular, and lighter in colour near the periphery, and 

 the edge is slightly irregular. (Percy Frankland.) 



GELATINE TUBES. It grows stewly, forming numerous minute yellow centres 

 in the track of the needle, whilst on the surface it produces a shining lemon- 

 yellow expansion consisting of small hump-like protuberances. In nine days 

 the surface growth was still very restricted, but had formed a depression filled 

 with lemon-yellow semi-liquid matter. Even after eighteen clays there was but 

 little change in the needle-track, but the surface-depression, which was con- 

 siderable, was filled with liquid, at the bottom of which was a lemon-yellow 

 deposit. (Percy Frankland.) 



AGAR-AGAR. Forms a thick chrome-yellow moist mass, extending over the 

 surface. 



POTATOES. Grows very slowly, producing sulphur-yellow colonies restricted 

 to the point of inoculation. 



BROTH. After nine days the liquid is clear and free from pellicle, whilst a 

 lemon-yellow deposit collects at the bottom. (Percy Frankland.) 



