THE BIOLOGY OF THE BACILLUS VIOLACEUS LAU- 
RENTIUS OR PSEUDOMONAS JANTHINA. 
BY GRACE ROODDE RUEDA. 
The first mention of pigment producing growth is of 
great antiquity. It aroused the suspicion of the ancients, 
worked on the religious zeal of the people of the Middle 
Ages, and today solicits the study and investigation of 
modern scientists. In the light of our present cultural 
means of study the chromogenic group of bacteria is 
especially interesting. The products can be easily watched 
and as easily segregated. Each organism can be classed 
together under color and can thus be definitely recognized; 
The B. prodigiosus is such an organism. It responds fully 
to laboratory methods. It has been thoroughly studied 
and is one of the first specimens to be put into the hands 
of beginning students. Among the yellow bacteria that 
have been carefully investigated may be mentioned Sarcina 
aurantiaca and S. lutea. 
In early days religious teachers, such as the Egyptian 
priests and the Zoroastrians, forbade their disciples many 
kinds of food, among which were white cooked beans. 
Pythagoras no doubt took his antipathy for beans from 
these sects. However, he said that beans were not whole- 
some, because if placed in the moonlight they would 
change to blood. Once' when the besieging army of 
Alexander the Great lay before the city of Tyre their 
bread was found to be bloody red. This' created a great 
consternation among the soldiers. The priests, when 
called upon to explain the mystery, said that it meant 
that a bloody fate awaited the people inside the city wails 
because the red color was found on the inside of the loaf. 
( 121 )* 
