J. Johnstone 
415 
PLATE XXII. The genital organs. 
Fig. 12. Horizontal section of the part of the proglottis lying behind the genital iJapilla. 
The proglottis is nearly mature. Mag. 100 dia. 
Fig. 13. A testicular follicle. The section passes nearly in the horizontal plane of the 
organ. The explanation of the Greek letters is given in the text at pp. 397, 398. 
Fig. 14. Ovarian eggs. Mag. 1500 dia. 
Fig. 15. A testicular follicle cut in the same plane as that represented in Fig. 13. The 
latter figure represents the more mature phase. Mag. 900 dia. 
Fig. 16. Part of a transverse section of the wall of the uterus. The lower -side of the 
figure represents the surface which faces the lumen. Mag. 500 dia. 
Fig. 17. Longitudinal section of a follicle of the vitelline gland. Mag. 500 dia. 
Fig. 18. Transverse section of an immature testicular follicle. Mag. 900 dia. 
PLATE XXIII. Integument, musculature, etc. 
Fig. 19. Part of a transverse section of the integument and underlying tissues in the 
region of the least mature segments. 
Fig. 20. Part of a tangential section through the integument. The section is thick 
enough to contain both the transverse and longitudinal integumentary muscle fibres. 
The thin horizontal lines represent the former, and the thick wavy lines the latter. 
Oil-immersion lens. 
Fig. 21. Part of a transverse section through the integument and underlying tissues of a 
nearly mature segment. 
Fig. 22. A small part of a transverse section through the musculature of a proboscis 
bulb. The latter is greatly contracted. The diameter of the lighter shaded “ fibres ” 
is about 2 /x. 
Fig. 23. A similar section from a proboscis bulb. The diameter of the “fibres” is 
about 3 IX. 
Fig. 24. Transverse section of the retractor muscle of the proboscis. 
Fig. 25. Part of a transverse section through a mature proglottis showing the shell gland 
opening into the oviduct. 
PLATE XXIV. The mature proglottis. 
A semi-diagrammatic representation of the organs of a ripe proglottis. The relative 
positions and proportions of the various organs are as accurately preserved as 
possible; but, as in PI. XXI the coils of the uterine canal and vas deferens are 
drawn more simply than is actually the case. 
