Fig. 14. A Plerocercoid with the terminal head either lost or strongly 



retracted, but with a greatly outstretched head-bud. 

 Fig. 15. A Plerocercoid moderately stretched out and with irregularities 

 of contour in the anterior parts. 



Fig. 16. Cross-section through the anterior part (head region) of a Plero- 

 cercoid. Magnified 100 times. %., lateral nerves, ex., excretory 

 vessels in section. The black dots represent partly nuclei and partly 

 longitudinal muscular fibers in section. 



Fig. 17. Cross-section through the posterior part of a Plerocercoid. Mag- 

 nified 100 times, cal., calcareous bodies, ex., excretory vessels. 

 mus., bundles of longitudinal nuiscular fibers, which, in many other 

 parts, are represented by the larger black dots. r. n., reserve nutri- 

 tive-matter in capsule. 



Fig. 18. Head-end of a Plerocercoid fully stretched out, showing the simply 

 rounded tip. Drawn from a specimen clarified with glycerine, 30 

 times magnified. Excretory vessel in part strongly swollen on account 

 of the stowing of the liquid contents. 



Fig. 19. A Plerocercoid pressed under glass; over-stained with carmine 

 and afterwards bleached with caustic potash. Black dots represent 

 well-stained calcareous bodies, which are absent in the head region. 

 Keserve nutritive-matter (r. îz.) in the form of numerous balls. A 

 pair of excretory vessels (ea;.) in the anterior parts. Magnified 30 

 times. 



Fig 20. A section through an irregular-shaped piece bearing a number of 

 buds or heads, parts of which are seen in two places (A.). Other 

 lettering as in fig. 17. Magnified 50 times. 



Fig. 21. A horizontal section through the nearly fully evaginated head- 

 end of a Plerocercoid. Lettering as in fig. 17. Magnified 50 times. 



Fig. 22. A horizontal section through the hind parts of a Plerocercoid. 

 Lettering as in fig. 17. Magnified 50 times. 



Fig. 23. Section of a worm-cyst lying in the subdermal connective tissue. 

 About 8 times magnified. 



