706 Laura Florence 



the duct they interlace, giving the appearance of a netwoi'k near the 

 epithelium. The slender part of the ejaculatory duct has a small, round- 

 celled epithelium, but in one quarter of the wall it is thickened and 

 projects into the lumen as a more or less blunt cone, which, in the passing 

 of the duct to the penis, forms its dorsal wall. 



In gross dissection of the parts no accessory glands have been found. 

 Patton and Cragg (1913:559) describe and figure small glands in Pediculus 

 vestmienti at the junction of the vasa deferentia with the seminal vesicles, 

 but such are not present in Haematopinus. Nuttall (1917 a : 308) mentions 

 the accessory glands of Pediculus as lying on the muscle of the dorsal 

 surface of the basal plate and undergoing passive movement along with 

 the ejaculatory duct and the penis at the extrusion of the copulatory 

 apparatus, but no such glands have been found in Haematopinus. It 

 may be that the place of accessory glands has been taken by the enlarged 

 glandular epithelium of the different parts of the ejaculatory duct. 



Female 



From the work of Landois (1864:14 and 1865 a: 48) it has long been 

 known that the Pediculidae possess polytrophic egg tubes. Graber 

 (1872:159) differed from Landois in his conception of the egg tubes, 

 and described them as telotrophic like those of the Hemiptera but gave 

 no figures, and subsequent work has shown him to be wrong. Strobelt 

 (1882, English trans. 1883:94) made the earliest reference to the ovaries of 

 Haematopinus suis, and he described them as bilocular. His findings in 

 regard to the structure of the tubes and the development of the eggs 

 confirmed the work of Landois. The classic work on the ovaries of 

 Siphunculata (Anoplura) and Mallophaga is that of Gross (1906:347) 

 in which he showed the close resemblance between the. two groups. He 

 studied four species, of which Haematopinus suis was one, and described 

 in detail the gross anatomy and histological structure of the ovaries 

 and the development of the egg. Mjoberg (1910:253) cited the work of 

 Gross but did not himself mention the female reproductive organs of the 

 hog louse. The female reproductive organs of the Pediculidae affecting 

 man have been described hy Pawlowsky (1908), who illustrated his 

 work with transverse and longitudinal sections (PI. II and III, figs. 4-12, 

 of reference cited) but included no drawing of the gross anatomy; 

 by Patton and Cragg (1913:560), who figured and briefly described the 



