34 
No. 96. Contagion experiment; spores derived from chinch-bugs 
received from Kansas State University. First bug dead in this 
lot in thirteen days; first appearance of Sporotrichum in twenty- 
six days. 
In Nop. 11, 12, and 86 —all infection experiments—and in conta¬ 
gion experiment No. 34, the material for which was derived from 
dead cabbage-worms, no visible effect resulted, the chinch-bugs ex¬ 
posed continuing without loss. 
It is further to be noted that in No. 29 of the above series, 
most of the bugs treated were alive after twenty-five days; that in 
No. 2 all were dead but one in eighteen days; that in No. 70, out 
of several hundred chinch-bugs exposed only twenty-four had suc¬ 
cumbed in eighteen days; that in No. 99 about one fourth were 
still alive in thirty-five days; that in No. 96 only a few were dead 
after the same interval, and that in No. 97 eighteen were living 
after seventy days had elapsed. 
In scanning these reports, I am not able to discover any sensi¬ 
ble difference of results corresponding to differences in the source 
of the fungus, whether derived from the body of the dead insect 
or from an artificial culture; neither does there seem to be any 
difference in the effect of cultures corresponding to the dif¬ 
ference in the number of generations grown successively upon ar¬ 
tificial media. 
With Miscellaneous Insects .—Miscellaneous infection experi¬ 
ments made with cultures ranging from the first to the sixth re¬ 
move from the original insect, numbered twenty in 1891. Arranging 
these, like the preceding series, in the order of promptness of the 
appearance of the Sporotrichum, they stand as follows: 
No. 64. Saw-fly larvae infected from original Thaxter culture, 
first remove from insect. Specimens under bell-jar. First dead 
in three days; external growth same day. In eight days all 
showed external growth but two. No loss in check after eleven 
days. 
No. 33. An infection of fifty cabbage worms; spores from arti¬ 
ficial culture of the fifth remove. Specimens in breeding-cage on 
damp sand. Three days, six dead; four days, twenty dead, and first 
external appearance of Sporotrichum. Seven days, all dead. 
Check in the meantime without loss. 
No. 65. Infection of saw-fly larvse; spores first remove from 
insect; specimens under bell-jar. First larva dead in four days, 
showing external growth of Sporotrichum. Eight days, all dead, 
and all but three with external fungous growth. No loss in check 
in eleven days. 
No. 36. Infection of one hundred cabbage worms with spores 
from various sources, second to sixth removes. Kept outdoors on 
food plant. First dead in three days; internal growth of Sporotrichum 
detected in six days; external growth in nine days. In seven days 
fifty-four dead, but with much hymenopterous parasitism. Sixty- 
six dead in nine days, and eighty-five dead in twenty-two days. 
In check, several dead with hymenopterous parasites, but no 
Sporotrichum. 
