JOURNAL OF MICROSCOPICAL SCIENCE. 
EXPLANATION OF PLATES XXVII AND XXVIII, 
Illustrating Professor Ray Lankester's Memoir On the 
Connective and Vasifactive Tissues of the Medicinal 
Leech.’’ 
Eig. 1. — Tissue from the neighbourhood of a nephridium, from a freshly- 
killed Leech, fb. Brown fibres of the entoplastic vaso-fibrous system, c. 
Branched and fusiform corpuscles of the ectoplastic connective jelly. 
Fig. 2. — A single corpuscle of the connective jelly ; nucleus stained by 
picro-carmine. 
Fig. 3. — Network of brown fibres from the neighbourhood of the nerve- 
cord. Less magnified than fig. 1. 
Fig. 4. — Brown fibre showing nuclei, n, and tubular character. S. Solid 
portion of the fibre. E. Hollow portion. Osmic picro-carmine prepara- 
tion. 
Fig. 5. — More decidedly tubular fibre of the vaso-fibrous system, showing 
in one part very thin wall devoid of granulations, and numerous nuclei pro- 
jecting into the lumen of the tube. The diameter of nuclei is y^th of an 
inch. Osmic picro-carmine preparation. 
Figs. 6 and 7. — Similar tubular fibres, showing nuclei and granular 
walls. 
Fig. 8. — Hsematophorous vessel (blood-vessel) with structureless wall, 
distended with hsemoglobinous fluid, and continuous with a brown tubular 
fibre, in which are free nuclei. From a chromic-alcohol section, stained 
with picro-carmine. 
Fig. 9. — Hsematophorous vessel with structureless wall, showing a few 
granules at gr , and terminating at fb in a fibre. 
Figs. 10 and 11. — Similar vessels to that drawn in fig. 8. 
Fig. 12. — A similar vessel to that drawn in fig. 9. 
Fig. 13. — Thin-walled haematophorous vessel containing free nuclei (cor- 
puscles), stained pink by picro-carmine. The haemoglobinous fluid has 
escaped. 
Fig. 14. — A similar vessel, with smaller free nuclei — the haemoglobinous 
fluid is here in position. Osmic picro-carmine preparation. 
Fig. 15. — Botryoidal tissue of the medicinal Leech, drawn from a hori- 
zontal section of a chromic-alcohol preparation. I am indebted to Mr. W. 
E. Roth, Demonstrator in the Zoological Laboratory of University College, 
for this excellent drawing. 
Fig. 16. — Surface view of the termination of one of the coeca of the 
botryoidal plexus in order to show the cells. Fresh preparation. 
Fig. 17. — Transverse section of caeca of the botryoidal plexus in order to 
show the relation of the cells to the lumen of the vessel. The haemoglo- 
binous fluid was entirely absent in this portion of the preparation. Chromic- 
alcohol section. 
Fig. 18. — Outlying portion of the botryoidal plexus in order to show the 
development of thick- walled botryoidal vessels (cc) as branches of a thin- 
walled haematophorous vessel (vv). Osmic teased preparation. 
Fig. 19. — Caecum of the botryoidal plexus in optical section, showing the 
coagulated haemoglobinous fluid surrounded by the swollen granular cells of 
the vessel-wall. 
Figs. 16, 17, and 19 arc more highly magnified than figs. 15 and 18, 
