65 
(Pieris rapw) disease, but a microscopic examination shows the former 
to be a rather small bacillus. 
A similar observation was made June 10, when one of a lot of Boll 
Worms kept in a breeding cage for life-Jiistory purposes was found 
dead. A bacteriological study was made. The alimentary can al seemed 
to be the only portion of the body containing much liquefied matter, 
the fatty portions being rather slow to decay. Pressure of the decay- 
ing anterior third of the body forced out a drop of a rather golden- 
colored liquid, from which a broth culture was made. At the same time 
a pro-leg was snipped off with sterilized scissors, a platinum needle in- 
serted so as to miss the alimentary canal, and a second tube of broth 
inoculated. From each pure cultures upon agar-agar were isolated. 
In the beef broth the changes were the same as just described in the 
preceding study. Upon agar-agar a more profuse and vigorous growth 
was obtained, which was partly due to the fact that the tubes had been 
more recently prepared and were not so dry as in the first study. The 
film was smooth and white, with margins entire though irregular in 
some portions. 
This affection of Boll Worms is not very prevalent, though occasion- 
ally one is found in ears of corn dead or dying. From these in most 
cases the germ just considered can be isolated by the usual pure cul- 
ture methods. When affected, the larvae seem to lose their appetites, 
cease feeding, become rather sluggish, and appear somewhat disturbed. 
The color of the skin remains either partly or entirely normal, occa- 
sionally even for a time after death. At the same time, however, the 
tissues of the body are decaying and becoming watery, more especially 
along the alimentary tract. This condition at last imparts a grayish- 
brown or rose-tinted color to the body. 
Both cultures of this boll- worm bacillus were made from the pure 
ones on agar, and allowed to grow for eighteen days, when they were 
used in experiments 1, 2, and 3, which follow. 
Experiment 1. 
July 8 {5:30 p. m). — The husks of an ear of corn were torn aside and the silks and 
grains for a considerable space were well washed with the broth culture of the ba 
cillus. One nearly grown Boll Worm and one half grown, were placed within the 
husks, after which these were well closed down upon the ear. The ear was kept in 
a pot prepared as heretofore explained. 
The following day both larva- had fed freely upon grains of corn which had been 
drenched with the broth culture. No unfavorable symptoms. The second day the 
large worm had left the ear and entered tho earth for pupation. The small one was 
still feeding but showed no unhealthy symptoms. The third day the young larva 
molted. After this it continued to feed in the ear, pupating there and compl< 
its transformations by issuing as a moth July 27. The first pupa had hatched a few 
days earlier. 
l\xp> Hment P. 
During the same period of time four cabbage worms (Fieri* rapm) were fed upon 
a cabbage leaf which had previously been well drenched with a portion oi the broth 
14935— So. 29 5 
