JOURNAL OF MICROSCOPICAL SCIENCE. 
DESCRIPTION OF PLATE X, 
Illustrating Ernst Haeckel’s Monograph of Monera. 
Fig. 13 — 24. 1 lyxastrum radians. 
Fig. 
13. — My xast rum radians, encvsted, in the motionless condition ; a homo- 
geneous colourless ball of protoplasm, surrounded by a tough, 
structureless gelatinous covering, x 450. 
14. — The same, at the commencement of its development. The homo- 
geneous colourless ball of protoplasm begins to divide by radial 
cleavage into numerous conical portions, whose points rest towards 
the centre of the ball, while their rounded bases produce a mulberry- 
shaped outline towards the surface of the plasma-ball, x 450. 
15. — The same, further developed. The cone-shaped divisions of plasma, 
which resulted from the radial cleavage of the encysted plasma-ball, 
have assumed a spindle-shape, and each separate one has developed 
a siliceous covering. The encysted Myxastrum now forms a globular 
sporangium, which encloses numerous spindle-shaped, siliceous spores. 
X 450. 
16. — The same sporangium as in fig. 15. The focus of the microscope 
is placed so that one can perceive the star-like arrangement of the 
siliceous spindle-shaped spores. X 450. 
17. — The empty siliceous shell of a spore ; the protoplasm -body has already 
slipped out. x 450. 
18. A spore whose contents have just begun to glide out. from the siliceous 
shell. X 450. 
19. — The same spore as fig. IS, but seen a short time later. There is now 
only a little sarcode remaining in the siliceous shell. X 458. 
20. — The homogeneous sarcode-body of a spore which has entirely left its 
siliceous shell (fig. 17), and has assumed a globular form, x 450. 
21. —The same sarcode-ball as fig. 20, seen some time afterwards. Fine 
striae begin to appear everywhere on the surface, x 450. 
22. — A somewhat older globular Myxastrum , whose radial pseudopods are 
already longer. X 450. 
