Bacterial Disease of tlie Squash-bug. 347 



GROWTH CHAUACTETJS WITH VARIOUS NUTRIENT MEDIA. 



Solid media. — On nutrient gelatine this organism makes 

 a rapid growth. Several stab cultures were made on 

 Sept. 30, and the tubes were kept at a cool, living-room 

 temperature. In two days the central needle-path showed 

 a growth throughout its whole extent, and on the third 

 day liquefaction had begun. The appearance is at first 

 that of a short cylindrical or rotund air cavity, from 

 the lower surface of which projects the tapering liquefied 

 portion for about one third of the inoculation line, show- 

 ing a considerable precipitate in the lower part. On the 

 third day the liquefied portion was considerably extended, 

 occupying an area shaped like an inverted lamp chimney, 

 along the middle line of which extended the undulating 

 precipitate-like bacterial formation. In the course of 

 one week, three fourths of the gelatine was liquefied, and 

 the bacterial growth was scattered through the lower 

 portion in a flocculent manner. The remainder of the 

 gelatine was soon liquefied, the flocculent material set- 

 tled to the bottom, and with the exception of a slight 

 turbidity the color of the liquefied portion remained un- 

 changed. After standing for about one month, and 

 before any great amount of evaporation had taken 

 place, the light amber-color was changed to a deep 

 reddish amber, and the color became more pronounced 

 as evaporation advanced. 



On slices of sterile potato kept in a moist chamber, 

 this organism makes a profuse growth in two days. 

 About this growth there is nothing especially typical; 

 but the dirty-white color is well marked, and the thick 

 film of growth shows a strong tendency to become 

 lobulated on the margins. 



Liquid media. — Fluid cultures were made to determine 

 the nature of the growth, and also to ascertain how the 

 organism might be propagated in considerable quantity 

 for infection exjieriments, if the latter should prove de- 

 sirable. In bouillon a considerable turbidity is produced 



