78 
in the incubator. October 3 this had formed two very small 
colonies of rather poor and irregular growth but, seemingly pure 
Micrococcus insectorum. The bacteria were usually in couples, 
but occasional examples were of irregular form, swollen at one 
end or abnormally slender, peculiarities traceable perhaps to 
the effect of the corrosive sublimate. 
Several other attempts with agar and gelatine and with fluid 
media were neither more or less successful than the foregoing.* 
all leaving a margin of doubt whether the original form reap¬ 
peared in the culture,— a doubt which could only be removed by 
infection of healthy insects from these cultures and the reappear¬ 
ance under such circumstances, in the alimentary canal, of the 
form originally occuring there. Unfortunately for the conclu¬ 
siveness of this work, it was impossible to find at any time when 
these cultures were in progress any lot of chinch bugs which 
would not show this Micrococcus spontaneously if kept for a 
little time in confinement, and the investigation consequently 
remains in an unfinished state. The fact is worthy of special 
remark that lots of chinch bugs kept for several days in the 
dry air of the laboratory, imprisoned under a large bell jar on 
a varnished table, continued to die in numbers with this bac¬ 
terial disease, and finally all perished. Other fungus attacks 
were invariably arrested by such conditions, the air being prob¬ 
ably too dry to permit the Entomophthora or the Sporotrichum 
to flourish. 
Sporotrichum globuliferum, Spegazzini. 
The unquestionably parasitic character of this fungus, the 
terrific destruction of chinch bugs to which it certainly contributed 
in 1888 and 1889 in Illinois, the ease with which it may be culti¬ 
vated artificially in quantities, and the great variety of insects 
which we have found it to attack, make it one of the more im¬ 
portant fungus parasites of insects from an economic point of 
view, and will doubtless justify the fullest treatment possible at 
the present time. 
It was first detected on the chinch bug near Shattuc, in Clin¬ 
ton county, Illinois, July 7, 1887, in a field of corn beside ripe 
wheat, which was then being invaded by chinch bugs from the 
latter crop. On the outer rows, still black with insects, I found 
several adults and a few young dead and fastened to the sur¬ 
face of the leaves by a white fungus growth. On some of these 
specimens, bottled dry, the fungus continued to develop freely, 
finally almost covering them, and forming upon the surface the 
characteristic spherical heads of minute spores. Specimens 
picked to pieces in glycerine showed the body crowded every¬ 
where with the fungus mycelium, in the oldest cases all the 
tissues having disappeared with the exception of a fragment of 
muscle here and there. 
* See foot-note p. 82. 
