Contagious Diseases of Insects. 293 



those already treated. On the 15th another larva pupated, and 

 a seeoncl died during the night which had been reported slug- 

 gish the previous day. The body was shrunken, not very soft, 

 a little brown, but the general color was still the usual green. 

 The fluids of the specimen were very white and thick, aud con- 

 tained vast numbers of mulberry granules, both singly and in 

 clusters, together with great quantities of oval micrococci (some 

 in chaplets of four) and occasional individuals of Bacterium, 

 some of the latter in actual luotion. The mulberry granules 

 were strictly spherical, and varied in size from 1.5 ju. to 3 ^u in 

 diameter. 



Another larva which died was originally paler than 

 natural, but not white. Before examination it bad blackened 

 and turned very soft, but was not deliquescent. Slides pre- 

 pared from it contained dehris of tissues, muscular and other, 

 and vast numbers of minute spherical micrococci from .5 f*. to 

 .7 A* in diameter. No flagellar motion was detected in the fresh 

 slides, and no other forms are apparent in the stained mounts. 



Another example, small and shrunken, a little discolored, 

 dried up in a few hours, and became hard and brittle. It was 

 not especially studied. On the 17tli of the month the last 

 remaining larva died. It was not discolored, and I could find 

 no bacteria in the blood or other fluids. The cause of its death, 

 in fact, was not apparent. At this date a blackened pupa from 

 the cage, evidently not long dead, was found full of a blackish 

 fluid, which contained vast numbers of a small spherical 

 Micrococcus (.6 ;i* in average diameter, commonly in doubles) 

 and nothing else, except occasional mulberry granules 2 ^a in 

 average diameter. Of the individuals which puj^ated, six 

 emerged successfully, three were deformed, and two failed to 

 complete their transformations. 



History of the CJieck Lot. — This lot, placed in a new breed- 

 ing cage September 10 with fresh cabbage, was kept under 

 continued observation until the 28th. One of the specimens 

 died the first day from an accidental injury; one pupated on 

 the 12th; and two others were necessarily crushed in opening 

 the cage, having commenced to pupate on its sliding glass front. 

 On the 14th four examples pupated, and two more upon the 

 15th, at which time fifteen healthy larva? remained. The more 



