TAPEWORM PARASITIC IN THE STICKLEBACK, Navy 
EXPLANATION OF THE PLATES. 
Puate I. 
Figs. 1-7. Series of scoleces, showing variation in shape and size. Fig. 3 is the 
normal form. XX 125. 
Fig. 8. Optical section of a proglottis. c.s., cirrus - sac; g-8.. genital sinus; 
lc, longitudinal excretory canal; ov., ovary; v., vagina; vas., vas 
deferens; vit., vitellaria; w., uterus. X 185. 
9. Longitudinal section of cirrus-sac. ¢.m., circular muscles ; e.w., outer, and 
i.w., mer wall of cirrus-sac ; U.m., longitudinal muscles; 7.m., retractor 
muscles; vas., vas deferens. XX 590. 
10. Transverse section of cirrus-sac, lettering as above. e.g. gland. X 870. 
11. Longitudinal section of odtype. o.d., oviduct; O.T., odtype ; Sh.G., shell 
gland; w.’, specialised part of uterus. > 870. 
Prats II. 
Fig. 12. Longitudinal vertical section through cuticle. ¢., ¢.’, outer and inner 
layers of cuticle; c.c.m., circular, c.l.m., longitudinal cuticular muscles ; 
i.l.m., inner longitudinal muscles; i.s., intercellular space; p.c., cell of 
parenchyma; s.c., cell of sub-cuticula. XX 600. 
13. Longitudinal section through vaginal aperture. s.m., sphincter muscle ; 
v.é., vaginal epithelium; v.g., vaginal gland; w.m., vaginal muscle. 
x 870. 
14, Longitudinal section through odclapt. c.e., cubical epithelium of oviduct ; 
0.é.5 outer oviducal epithelium; o.m., oviducal muscle; ov., ovary ; 
ov.b., connecting part of ovaries; s.a., muscle of odclapt. x 870. 
Figs. 15-19. Stages in the development of theegg. _m., first, m.’, second onchospheric 
membrane; 0., onchosphere; 0.h., onchospheric hooks ; #., aperture in 
secohd egg-membrane; y., yolk-follicles. < 870. 
Prate III. 
Figs. 20-22. Stages in the rupture of the second onchospheric membrane. X 870. 
Fig. 23. Onchosphere after rupture of second membrane. m., m.’, m.’’, first, second 
and third onchospheric membranes. XX 870. 
24, Hggs from ovary. e.g, Egg membrane; m., nucleus; m., nucleolus ; 
mk:, “ Nebenkérper.” 870. 
25. First division of egg. k.m., “Keimzelie”; mm, first onchospheric 
membrane; 7., nucleus; ~.’, nucleolus; v.c., vitelline cell. XX 970, 
26. Later stage, showing division of “ Keimzelle” nucleus. X 979, 
27. Stained section of fig. 26. 870. 
28. Section of three-cell stage. 870. 
29. Four-cell stage. Only three of the four products of “Keimzelle” division 
are Shown. v.c., vitelline cell. 870. 
30. Section of older egg. ch., “Chitinogenzellen”; 0., onchosphere ; sp., split 
between the two; v.c., vitelline follicles. x 870. 
31. Older ege. ¢.a., “couche albumineuse.” 
32. Section of uterine egg. X 870. 
) 
Prate IV. 
Fig. 33. Cyclops varius, containing young larve. J., larve. X 50. 
34. Transverse section of the Cyclops. X 142. 
35. Longitudinal section through head of a larva from Cyclops. ¢., ¢.’, outer 
and inner layers of cuticle; m., m.’, the two types of parenchymatous 
cell ; 0.9., space containing calcareous body: s., sucker. X 870. 
36. Longitudinal section through posterior end of larva. é.p., excretory pore. 
X 830. 
37. Larva from Cyclops varius.  s., sucker; c.b., calcareous body. > 155. 
38. Larva from an artificially infected stickleback. * 96. 
39. Young larva from a stickleback. X 95. 
40. Older larva. xX 95. 
[ Norz.—Since sending in this paper, I have been able to obtain 
a copy of Barbieri’s memoir (Central. f. Bakt. u. Pavas., Abt. i. 
