300 LIONEL JAMES PIOTON. 



Fig, C). — Granular mass and its envelope. (Bela-Haller's fluid.) ^y ob- 

 jective. 



Fig. 7.— Ditto. 



Fig. 8. — Granular mass and its envelope, from a section stained with 

 Elirlich's hsematein, showing " nucleus." —'. 



Fig. 9. — A mass divided into two. (Bela-Haller's fluid.) 



Fig. 10. — A mass divided into three, from a section. Parts are deeply 

 stained with hsematein. 



Fig. 11. — A portion of the medulla, ^y. From a section. 



Fig. 12. — Four chitinous bodies in a common envelope. (Bela-Haller's 

 fluid.) ^\'. 



Fig. 13 — Chitinous bodies after being boiled in caustic potash solution. 

 D (Zeiss). 



Fig. 14. — Chitinous body, surrounded by granules. yV. 



Figs. 15 — 19. — Formation of brown granules. yV objective. 



Fig. 20. — Heart-body, heart-wall, and adjacent peritoneum. Transverse 

 section, ^y. 



Figs. 21 and 22. — Leucocytes with pigment, fresh, ^y. 



PLATE 21. 



Fig. 23. — Siphonostoma diplochsetcs. Transverse section through 

 heart-body at the origin of the heart, x 85. 



Fig. 24. — S. diplochsetcs. Transverse section of heart-body. ^y. The 

 nuclei stained with htematein (the dark granules, red in the fresh tissue, were 

 stained deep greenish blue with hsematein ; these are shown in the figure in 

 black). 



Fig. 25.— An isolated cell of the heart-body of S. diplochsetos, in its 

 natural colours. ^2'. 



Fig. 26. — Similar cells, after maceration and teasing in Bela-Haller's 

 fluid. ^'. 



Fig. 27. — Isolated cell of heart-body of Lanice conchilega. ^y. Bela- 

 Haller's fluid. 



Fig. 28. — Lanice conchilega. Composite granule, jy. 



Fig. 29. — Polycirrus, amoeboid corpuscle, with amber-coloured granules; 

 fresh, ^y. 



Figs. 30 and 31.— Polycirrus, pigmented corpuscles; fresh, ^y. 



Fig. 32.— Isolated cell of heart-body. Terebellides Stroemii. Bela- 

 Haller's fluid. Stained with methyl green. 



