20 
were not at all plentiful. It remains to be added that the larger 
Heteropterous insects, mostly Metapodius, were abundant upon Sola- 
num at this time, and that probably great numbers of the remaining 
immature worms fell a prey to them. 
The cannibalistic habits of the Boll Worm are also of importance and 
must be considered here. First to be mentioned in this connection is 
the fact that the Boll Worm devours its larval skin as soon as molted 
and does so before it begins feeding on vegetable matter again. When 
collecting worms from the fields considerable care must be exercised to 
have a box or basket large enough to receive some foliage, in order that 
the worms may not iujure and destroy each other before reaching the 
laboratory. In the breeding cages the Boll Worms not only attack 
each other, but almost any other larva placed in the arena. In a state 
of nature they have not been observed to deliberately attack each other 
except in corn, especially when the field was a small one, and great 
numbers of eggs are deposited and hatched on the same plant, so that 
an unnatural number of worms expect to feed upon the same ear of 
corn. The same may be said concerning the "bud," if the plant be 
young yet. 
In several instances where such small fields of corn were found near 
large cotton fields, examination of the ears resulted in finding from three 
to six worms of various sizes in them. A day or two later when the 
same ears were examined some of the smaller ones were found to be 
badly bitten (enough to cause death), and some dead ones whose bodies 
gave evidence of a violent death. None of the worms had been de- 
voured, and it seems that the warfare had been brought about by the 
worms intruding on each other's territory, as feeding progressed, and 
that nothing more was done than would maintain their positions. 
THE PUPA. 
A number of Boll Worms which had been fed on bolls in breeding 
cages matured and were placed in a fruit jar about two-thirds full of 
earth. The worms at once entered the earth, formed their cells, and 
pupated about 2 or 3 days after. The pupa is a beautiful green at first, 
but soon turns to a light brown or mahogany. When all the worms 
had pupated the earth was examined to determine something about 
the depth of the burrows and cells and the manner in which they were 
made. The earth had been recently placed in the jar and was quite 
loose when the worms were placed on it. The depth of the burrows 
varied from 2J to 5 inches and throughout their course were partially 
filled with loose earth. The cells were all much larger than any part 
of the burrows and extended upward from the end of the same. One 
worm had come to the surface of the glass in making its burrow, 
and was observed while making its cell. The worm seemed to test 
carefully every part of the wall of the cell to see that all was firm. The 
whole surface was then thinly coated with a sticky fluid, at the same 
