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Biology of Phthirus pubis 
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Fig. 7. Chart showing the positions occupied on successive days by a Phthirus from 
the day it hate lied out and anchored itself as a first stage larva (Day 1) until it died 
(Day 33). The black spots denote the anchorages, M the three successive moults 
ending in ^ where it became adult. The dotted line shows where the male was trans¬ 
ferred higher up the leg. The quadrangular contour indicates the actual area of skin 
in which the movements took place (natural size). The movements of the female in 
the identical area are recorded in Fig. 8. 
