s 
og 
Fig. 7. The se Sena pret (Micrococcus insectorum, 
Burrill). From artificial cultivation in beef broth. Magnified 1000 di- 
ameters. 
On the 22th of September, several stained and mounted slides of 
this material and of the contents of the various culture tubes, were 
submitted to Prof. Burrill, of Champaign. The slides were carefully 
studied by him, and to him I owe the determinations of the various 
forms observed. The insect bacterium was described by him under 
the name of Micrococcus insectorum, in the Eleventh Report of the 
Illinois Industrial University, in the following terms: 
‘““Cells obtusely oval, isolated or in pairs, rarely in chains of several 
articles; .000022 in. wide, and .000027 to .00004 in. long, usually 
about .000032 long; movements oscillatory only ; forming zodgleea (?). 
In the digestive organs of chinch-bugs (Blissus leucopterus), * * * 
The organism is somewhat similar to, but not identical with, Mi- 
crococcus bombycis, the ‘disease germ’ of the silk worm, which was 
so fatally destructive to the silk industries of France, and which 
became the subject of the successful studies of Pasteur. The form 
of the organism approaches the typical shape of Bacterium, being 
oval and short-cylindrical, with rounded ends; otherwise the char- 
acteristics are those of a true Micrococcus.” 
Although this description was made from a slide of specimens 
cultivated in*the beef infusion, these had been previously carefully 
compared with fresh specimens from the insects themselves, and 
ascertained to be unquestionably identical. | 
In a test-tube of corn infusion boiled and left standing open in 
the laboratory, where the examinations of these various fluids were 
