D. Keilin and G. H. F. Nuttall 
309 
unequal size, being scattered upon the back of the abdomen. At times the 
fragments are reduced to but two or three minute chitinous spots, in which 
case other characters which distinguish hermaphrodites indicate that the spots 
actually represent rudiments of dorsal bands. The bands are generally com¬ 
plete in hermaphrodites of predominantly male character and are fragmented 
in those with predominantly female character, but there are numerous excep¬ 
tions, as exemplified, for instance, in Plate XII, where an hermaphrodite 
having male characters is shown with fragmented bands; similarly, herma¬ 
phrodites with predominantly female characters may at times have bands 
complete (Text-fig. 9 a). In no case did we find a specimen with the bands 
developed merely on one side. 
Legs. 
Most hermaphrodites show the characters of both sexes in their leg 
structure, the first pair being of male type, the third of female type (Text- 
fig. 23). It follows that in copulation these legs 
may function normally, either as in the male or 
female respectively. In all cases the structure 
of the corresponding legs on both sides is 
identical. 
Longitudinal muscles of abdomen. 
In hermaphrodites of predominantly d char¬ 
acter, the dorsal and ventral muscles running 
longitudinally from segment to segment are 
generally of male type, but exceptions occur 
wherein the ventral muscles are of female type 
or even more reduced than in the normal female. 
In hermaphrodites of female type the dorsal 
muscles are usually of male character and the 
ventral muscles as in the female; exceptions 
occur, however, in which the muscles of both 
sides are as in the normal female. 
Ventral plates of male and female. 
The ventral plates in hermaphrodites vary 
greatly in their structure and relations to each 
other. Thus (1) the d plate may be present 
alone and be of normal form; (2) the d plate 
may be normal and the $ plate reduced and partly invaginated; (3) the d 
and $ plates may coexist and both be normal in shape; (4) the d plate may 
be bipartite and the $ plate normal; (5) a half of the bipartite d plate may 
be free, the other half being fused to the ? plate to form what we term its 
antero-lateral extension; (6) the two halves of the d plate may be fused with 
Text-fig. 23. Pediculus humanus, 
cross between capitis and cor¬ 
poris, the 3 legs of one side 
showing d character of leg I, and 
$ character of leg III which con¬ 
sists in the presence of a femoral 
spur (fem.sp.). (N. del.) 
