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The Life-History and Anatomy of Moths 
encased in hard chitinous rings and sheathings. As a measure of 
protection during this stage, the insect, before transforming into a 
pupa, descends into the earth, and forms there a cell at a greater or 
lesser depth beneath the surface, or else weaves a cocoon of silk 
about its body. In some cases the 
transformation takes place at the 
surface of the earth under leaves or 
under fallen branches and the loose 
bark of trees. In almost all such 
cases there is apparently an at¬ 
tempt, though often slight, to throw 
a few strands of silk about the body 
of the caterpillar, if only to hold in 
place the loose material amidst which transformation is to occur. 
The forms assumed in the pupal stage are not as remarkably 
diversified as in the larval or imaginal stages. The pupae of 
moths are generally brown or black in color, though a few are 
more or less variegated. The bright golden and silvery spots 
which ornament the pupae of many species of butterflies, causing 
them to be called chrysalids, are seldom, if ever, found. 
While the change into a pupa might at first sight appear to 
the superficial observer to be disadvantageous because of the loss 
of motion and the imprisonment 
within narrow bounds, it neverthe¬ 
less distinctly marks a progression 
in the life of the creature. The pupal 
case contains within it the moth, as 
may easily be ascertained by a care¬ 
ful dissection made in the very earliest 
period after the change has occurred, 
and which becomes very evident at a later time when the period 
of the pupal life is drawing to its close. 
In the cocoon or in the cell in which pupation has taken place 
will always be found the exuviae, or the larval skin, etc., of the 
caterpillar, which have been cast off. 
When the time comes for the perfect insect to emerge from 
the pupa, nature has provided methods by which escape from 
the prison cell underground, or the tightly woven cocoon, can 
be effected. In the case of those pupae which lie deeply buried 
Fig. 6.—Pupa of Cut-worm 
in earthen cell. (Riley.) 
Fig. 5.—Pupa of Telea 
polyphemus. (Riley.) 
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