16 
used, a description of that will serve, with slight variation, as 
typical of all of them. 
The specimen from which this form (Jsaria vexans) was ob- 
tained, was found in the insectary at Cornell University. It 
was completely covered with a felted white coat of mycelium, 
bearing patches of the creamy-white conidia. A microscopic 
examination showed the fine anastomosing threads bearing 
minute spherical conidia or spores in clusters, which as they 
increase in size by the constant addition of conidia, assume the 
form of compact semi-spherical heads identical with those 
seen in the plate culture. When this disease attacks the 
chinch-bug it covers it entire body, with the exception of the 
legs and some small parts which project from the snow- 
white covering (Fig. 6). When grown in artificial plate-culture 
the development is as follows: 
the nearly spherical conidia be- 
comes swollen, and produces a 
slender germ-tube, which grows 
in asinuous line, Fig.7, h, branch 
ing occasionally, and producing 
many long cylindrical conidia in 
the agar. These are born at the 
ends of filaments,and each sporeis 
successively pushed aside by that 
next produced, resulting usually 
in a cluster of spores placed side 
by side (Fig. 7, 0). Branching 
soon commences, and septa are 
often present just below the bases 
of the branches. At the end of 
about three days the growth ap- 
pears above the agar in loose, 
Fee oa oOo e ey coumiots cottony filaments cuchealana 
becoming circular in form and finely radiate. After one more day 
the conidiaappear. Short sterigmata bear one or two conidia on 
short pedicles. (fig. 7, /, k.) These conidia increase in number 
and the sterigmata lengthen and multiply until at theend of a 
week large heads are formed. (Fig. 7,m.) The threads anas- 
tomose freely (Fig. 7, n.), In places where the colonies are 
crowded they sometimes assume a Stellate form. Fig. 8, Plate 2, 

