G. H. F. Nuttall 
31» 
hook it into the vagina. Both sexes defaecate whilst these efforts 
continue, the amount voided by the female being greatly in excess of 
that voided by the male. The faeces, or rapidly inspissating masses 
of the freshly ingested blood are pushed to one side by the dilator as 
they get in the way, and finally, after a struggle lasting about a couple 
of minutes, the dilator penetrates the vagina. The dilator now gives 
the male an additional hold on the female and it is extruded still further 
and rapidly pushed in and out, whilst penetrating more and more deeply. 
After some 30^0 strokes, when it has penetrated to its full length, 
corresponding to the depth of the vagina, the parts are seen to glisten 
Fig. 11. Pediculua humanus. The male having dilated the vagina as shown in Fig. 10, 
has extruded his vesica with its distal penis into the vagina, and withdrawn the 
dilator whose point is flexed on his back. He is now firmly anchored by the teeth 
on the vesica adhering to the walls of the vagina, and the couple walk away to a retreat. 
This, and the preceding figure were drawn from hasty sketches subsequently amplified 
from killed specimens. 
with secretion. The female’s abdomen now suddenly shortens, owing 
to the last two segments becoming somewhat telescoped, apparently 
through the forceful efforts of the male. The dilator continues to 
penetrate deeply for a few strokes, it is then quickly retracted, having 
been rapidly replaced by the everted vesica. The dilator is immediately 
flexed downward and out of the way on the male’s back, having served 
its purpose in widening the vagina. At no time do the so-called gono- 
pods appear to come into play as graspers or otherwise. The dilated 
vesica fills the whole lumen of the vagina which it distends almost ta 
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