no 
(Section 13. 
„ 14. 
„ 15. 
Mouthparts of Pediculus 
„ io. 
., 17. 
18. 
19. 
20 . 
21 - 
24. 
25. 
Stabbers at region shown in sect. 12; note the darkly stained dots in the tissue of 
the dorsal stabber and the tissue of the lumen of the ventral stabber. 
Showing anterior portion of dorsal ( d.s.pr .) and ventral ( v.s.jjr .) parts of the pro¬ 
tractor muscle of the sac 
Showing merging of the dorsal and ventral parts of the retractor of the sac; the 
flattening of the dorsal stabber; the darkly stained peripheral portion of the tissue 
of the dorsal stabber; the region where the ventral element of the ventral stabber 
rises up from the floor of the sac. 
Showing the separation of the lateral elements of the dorsal stabber; the flattening 
of the dorsal element of the ventral stabber and its separation from its ventral 
fellow except for a thin connecting membrane. 
Showing lumen in the tissue of the dorsal stabber; the floor of the sac formed by the 
ventral element of the ventral stabber only; the insertion of the posterior retractor 
muscle of the sac ( p.s.r .); the broadening of the dorsal element of the ventral 
stabber. The black dots in the lumen are displaced fragments of the dorsal stabber. 
Parts slightly displaced. Showing dorso-lateral position of the protractor muscle 
of the sac; the tissue of the dorsal stabber and the salivary pipe above the dorsal 
stabber; the flat, broadening elements of the dorsal stabber; the grooved portion 
of the dorsal element of the ventral stabber; the rami of the ventral element of 
the ventral stabber; the two insertions of the retractor muscles of sac (p.s.r.), the 
main muscle and ( a.v.st.r.) a smaller muscle associated with it. 
Similar to sect. 18; showing insertion of retractor muscle of the dorsal element of 
the ventral stabber ( v.st.r .); fibrous connection of dorsal stabber to sac (f.t.) and 
ventral stabber. 
Similar to sects. 18 and 19; showing beginning of bifurcation of the dorsal element of 
the ventral stabber; retractor muscle of dorsal element of ventral stabber (v.st.r.) 
now running along the ramus of the ventral element. 
23. Showing insertion of the retractor muscle of the dorsal stabber (d.st.r.) and the 
associated muscle (pi.v.st.r.) which ultimately runs along the posterior part of 
ventral element of the ventral stabber. 
Note the disappearance of the retractor muscle of the ventral element of the ventral 
stabber (v.st.r.); the presence of the muscle ( p.v.st.r.) associated with the retractor 
of the dorsal stabber. The tissue around the salivary pipe was lost in preparing 
the section. 
Similar to sect. 24. The salivary pipe appears to be thickening. The muscles are 
very close together. 
Pawlowsky’s Glands (P.gl., PL VI, fig. 1 and Text-figs. Ill, VI). The 
significance of these glands is not understood. The large orifice of each gland 
opens into the sac slightly more than half way along its length. The gland 
secretion appears to be poured into the lateral floor grooves. Each gland lies 
mainly above and laterally to the sac and resembles a tube looped twice on 
itself (Text-fig. VI, A). The walls of the tube are thick and consist of one 
layer of large glandular cells (Text-fig. VI, B). Three regions may be distin¬ 
guished: (1) the outer and upper third, (2) the medial and (3) the lower and 
terminal third. The lumen of the first third runs forward, downward, and 
* inward. It loops ventrally into the medial third whose cavity runs backward 
and downward. Next is another sharp ventral loop leading to the cavity of 
the terminal third which opens into the sac by a wide orifice and pours the 
secretion into the lateral floor grooves. I infer that the function of the glands 
is to provide a lubricant for the stabbers. 
