80 
but in the lower part of the tube, on the thicker agar, the myce¬ 
lium was still white and much more dense, and some of it was 
but just beginning to form its spores. 
No. 68. December 16. An infection experiment with pupae of 
the “woolly bear” (Spilosoma virginica) and other Arctian pupae. 
Seven pupae were treated with Isaria spores from No. 67 by rub¬ 
bing them over the spiracles and between the segments of the 
abdomen. They were then placed in a covered jelly-glass. One 
moth and several hymenopterous parasites emerged, and one dead 
pupa was found February 10, 1893, with a slight fungous growth 
on its body. 
No. 69. March 22. An agar culture to test the vitality of 
Sporotrichum spores taken from the original Thaxter culture (No. 
7, 1891). No white fungus appeared. A fungus which produced 
spores of a greenish tinge appeared in the tube, and fruited 
abundantly March 29. 
No. 70. March 24. A second agar culture, like No. 69, and 
yielding similar results. 
No. 71. May 5. Test-tube cultures on agar infected with 
Sporotrichum spores from chinch-bugs dead with that disease, 
taken from a stock cage, kept in the insectary, in which the fun¬ 
gus appeared spontaneously. The bugs were originally collected 
at Litchfield, Illinois, September 23, 1891. Eight test-tubes of 
agar were infected from this source. The white fungus made a 
vigorous start, but was soon destroyed by a common mold which 
appeared May 9. Experiment a failure so far as Sporotrichum 
was concerned. 
No. 72. May 11. Eight test-tube cultures precisely like the 
foregoing (No. 71), the spores coming from the same source. 
The white fungus had appeared in all the tubes four days later. 
Two tubes contained a seemingly pure culture, while in the others 
a common mold had also grown. These cultures grew slowly 
because of cool weather, and by May 20 the molds had fruited, 
and were being suppressed by the Sporotrichum. The latter had 
produced ripe spores by May 25, and those from the purest of 
these tubes were used for infecting corn-meal cultures in the ex¬ 
periment immediately following (No. 73). 
No. 73. July 7. Fruit-jar cultures on corn meal and beef broth. 
Fourteen fruit-jars were each supplied with two small sacks of 
corn-meal thoroughly soaked in beef broth (prepared like No. 
50), and sterilized on two successive days for two hours each day, 
at a temperature varying from 100 to 120 Cent. Spores from 
agar culture No. 72 were then introduced. The fungus had begun 
to grow on the medium by the 9th. A slight mold appeared in 
some of the jars the 11th. Sporotrichum spores were forming the 
15th, and were generally ripe three days later, except that exces¬ 
sive moisture retarded the growth in some of the jars. 
No. 74. June 20. A contagion experiment with Ischnodenius 
falicus, collected from wild grass. The bugs were placed on 
damp sand under a bell-glass with a dozen chinch-bugs dead with 
Sporotrichum, which came originally from the same source as 
