212 DISEASES OF THE COTTON PLANT. 
Whenever a young boll or bud is seen with the involucre, 
or outer calyx, called by some the " ruffle," spread open, it 
may be safely concluded that it has been attacked by the 
worm, and will soon fall to the ground and perish. The 
older bolls, however, remain on the plant ; and, if many of 
the fallen buds or bolls be closely examined, the greater 
portion of them will be found to have been previously 
pierced by the worm, the few exceptions being caused 
either by the minute punctures of some of the plant-bugs, 
from rain, or other atmospheric influences. Those injured 
by the worm can be distinguished by a small hole on the 
outside where it entered, and which, when cut open, will 
generally be found partially filled with small fragments of 
faeces. 
When very young, the boll-worm is able to suspend 
itself by a thread, if blown or brushed from the boll or 
leaf on which it rested. After changing its skin several 
times, and attaining its full size, the caterpillar descends 
into the ground, where it makes a silky cocoon, interwoven 
with particles of gravel and earth, in which it changes into 
a bright chestnut-brown chrysalis. The worms, which en- 
tered the ground in September and October, appeared as 
perfect moths about the end of November. 
A boll-worm, which was bred from an egg found upon 
the involucel, or ruffle of the flower-bud, grew to rather 
more than a twentieth of an inch in length by the third 
day, when it shed its skin, having esten in the mean time 
nothing but the parenchyma, or teuder fleshy substance 
from the outside. On the fifth dav it bored or pierced 
through the outer calyx, and commenced feeding upon the 
inner ; and, on the sixth day, it agiin shed its skin, and 
had increased to about the tenth of an inch in length. On 
the tenth day it again shed its skin, ate the interior of the 
