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fastened to another plant, and in this manner a large number 
are deposited during the few weeks that the insect flies about. 
Most of the eggs are fastened to the ribs of the leaves, and 
only occasionally upon the leaf itself. 
The beautiful eggs, covered with fine granulations, are first 
of a honey-yellow color, which later changes to a reddish- 
brown. In about eight days a little caterpillar hatches from 
this egg. It is very black with a white band across the mid- 
dle. It feeds voraciously, sometimes doubling its length in 
one day, and attaining ten times its former bulk. After throw- 
ing off its old skin a number of times, it reaches its full size, 
when itis about one and three fourths of an inch in length. 
The caterpillar now possesses a pea-green color, with a trans- 
verse black band on each segment. In each of these black 
bands are four bright yellow spots, two on each side. The 
greenish head is also striped with black. This rather striking 
caterpillar does not hide like so many other caterpillars, but 
lives fully exposed upon its food plant. It possesses two horn- 
like organs, of a pale orange color, which are usually not vis- 
ible, being withdrawn into the first thoracic joints. When dis- 
turbed, these organs are extended in a threatening manner, or 
if the caterpillar is roughly handled they are projected to their 
fullest extent like two whips. They now emit a strong and 
unpleasant odor, somewhat like the bruised leaves of their food- 
plants. These organs are used todrive away parasitic insects, 
which try to fasten their eggs upon the caterpillar, and thus 
use it as a living cradle for their own offspring. Yet notwith- 
standing these defensive organs, parasites frequently succeed 
in their purpose. 
When the time arrives to transform into a chrysalis the cat- 
erpillar searches for a suitable spot and prepares for pupation 
by spinning a small silken carpet, to which the posterior end 
of the body is fastened, and it also forms a loose loop of silk 
around itself, so as to be more secure when the larval skin is 
exchanged for the pupal one. The pupa is brownish, and 
resembles a piece of wood so thoroughly as not to be readily 
detected. Soon afterwards the butterflies appear and produce 
a second generation. The insect winters as a chrysalis. 
The caterpillars are voracious feeders, and when numerous 
can cause considerable damage to such plants as parsnips, fen- 
