DESCRIPTION OF BACILLUS ALVEI. 33 



aration of any fluid takes place. Ultimately, however, it becomes 

 liquid, and after some months it assumes the appearance of a dirty 

 brownish j^ellow, glassy fluid. It is very slightly, if at all, acid. 



Gelatin tube. — In this medium the growth is seen on the surface 

 and along the lino of inoculation. On the surface a 'ramifying 

 growth takes place from the point of entrance of the needle; and 

 along the line of inoculation whitish, irregularly shaped masses appear, 

 which increase slowly in size. In a few days processes, wliich are 

 thickened at various points and clubbed at the ends, shoot out from 

 these masses. The ends of these processes do not seem to unite. 

 A beautiful appearance is obtained when only a few bacteria are 

 introduced along the line of inoculation. In a few days small round 

 colonies become visible to the naked eye. These increase in size, 

 and at about the tenth day shoots begin to appear, which radiate in 

 all directions from the central mass and become clubbed. As the 

 culture becomes older the radiating branches disappear, and only 

 small whitish collections of bacilli are seen at various points. Under 

 slight magnification, however, tracks of liquefied gelatin are seen 

 extending from the central mass to the wliitish collections. The 

 evaporation wliich takes place at the top gives rise to the appearance 

 of an air bubble. 



Beginning at the top the liquefaction of the gelatin advances 

 slowly downward until ultimately the entire tube is liquefied. After 

 two or three weeks there is a layer of liquid at the upper part, with 

 the growth as before described in the lower part. At first the Uque- 

 fied gelatin is clear excepting a loose, white, flocculent sediment 

 wliich is present. There may be a thin surface pelHcle. Later the 

 hquid becomes yellow, and gives off an odor similar to stale but not 

 'ammoniacal urine. This, Clieyne says, may better be described as a 

 "shrimpy" smell. ''The yellowish color and the peculiar odor," 

 Cheyne ^vrites, '4ias been found by Cheshire to be distinctive of 

 diseased larvse." 



Cheyne made also a few observations mth animals inoculated with 

 Bacillus alvei. A bluebottle fly which had eaten some of a milk cul- 

 ture of Bacillus alvei was placed under a funnel; the next day it was 

 found dead, and upon examination its juices were reported to be 

 full of the bacilli. Cockroaches were placed in a box with cultures, 

 but none of them died. A rabbit, some mice, and some guinea pigs 

 received cultures of Bacillus alvei subcutaneoush^, but in general only 

 negative results were obtained. 



A conclusion which Cheyne drew indicates that at that time he 

 was pretty thoroughly convinced that Bacillus alvei was the cause 

 of foul brood. The behef which he entertained was based upon his 



13140°— Bull. 98—12 3 



