42 Contagious Diseases of the Chinch-bug. 
calities were, in almost all cases, already infected with Sporo- 
trichum. 
3. Sporotrichum was found in healthy condition out of doors 
in January, 1895, and again about April 1, 1895. 
B.—That Sporotrichum survives all winter conditions which 
chinch-bugs withstand, and that artificial infection ts consequently 
in most cases not necessary is indicated by the following: 
1. Its survival of the winter of 1894-95. 
2. Probability that no conditions exist which would allow 
bugs to hibernate safely, and at the same time destroy wholly 
the spores of Sporotrichum, which it would seem have, on | 
account of their small size and great abundance, as good a 
chance of finding effectual shelter as the bugs themselves. 
3. General epidemics of Sporotrichum have been noted in 
other years before artificial spread of this disease was employed. 
4. The wide-spread occurrence in 1895 of a species of Em- 
pusa on chinch-bugs; a species which, so far as known, has 
not been artificially disseminated since the years 1892 and 1893, 
and then not widely. 
C.—The validity of the arguments under B, namely, that Sporo- 
trichum survives all winter conditions which chinch-bugs can with- 
stand, depends, toa great extent at least, on the following assumptions: 
1. That the winter conditions of 1894—’95 are similar to those 
of other winters, so far as the possibility of their effectually 
destroying Sporotrichum is concerned. 
2. That Sporotrichum will be present with chinch-bugs in 
their winter quarters, and be exposed to practically similar con- 
ditions. 
3. That the epidemics in question were present so generally 
that the possibility that the disease may have spread from 
certain specially favored localities is excluded. 
4. That the species of Empusa referred to bears the same re- 
lation to destroying agencies that Sporotrichum does, so far as 
the continuance of the disease from year to year is concerned. 
D.— Proposition B, namely, that Sporotrichum survives all winter 
conditions which the chinch-bug can withstand is opposed by the 
following : i 
sm Chinch-bugs from different localities have been kept, with- 
out the addition of infection, in moist jars or boxes and have re- 
ape 
