20 Davis . — Spore Formation in Derbesia. 
Fig. 7. Large and small nuclei within a young sporangium before the cleavage of the 
protoplasm. 
Fig. 8. A large nucleus heavily stained, showing the enveloping cytoplasm and radiating 
protoplasmic strands. 
Fig. 9. A large nucleus lightly stained to differentiate the granule at the base of each proto- 
plasmic strand. 
Fig. 10. A large nucleus and a neighbouring group of small degenerating nuclei in a region of 
cytoplasm free from plastids ; the latter are now much smaller than the plastids. 
Fig. 11. A group of smaller nuclei in an advanced state of degeneration ; the nuclear membranes 
of some have disappeared, and the nucleoli lie in the cytoplasm. 
Fig. 12. The beginning of segmentation by branching cleavage furrows cutting into the 
protoplasm from the periphery. 
Fig. 13. Spore-origins rounding up. 
Fig. 14. A spore-origin, showing the centrally placed nucleus from which protoplasmic strands 
radiate among the plastids, whose long diameters generally point towards the nucleus. 
Fig. 15. A nucleus lying near the periphery of a spore-origin, the granules apparently passing 
outward along the protoplasmic strands between the nucleus and the plasma membrane. 
Fig. 16. A stage similar to, but slightly older than that shown in Fig. 15. The nucleus and 
funnel-shaped arrangement of the protoplasmic strands with the granules is viewed from the interior 
of the spore-origin. 
Fig. 17. The granules are arranged in a circle just underneath the plasma membrane. 
PLATE II. 
Fig.. 18. Portion of a circle of granules underneath the plasma membrane, viewed from the 
exterior of the spore-origin. 
Fig. 19. The granules have fused to form a firm ring, the blepharoplast, above the nucleus and 
just beneath the plasma membrane. 
Fig. 20. A spore-origin after the formation and splitting of the blepharoplast ring, showing the 
nucleus now in the centre of the protoplast and the plastids again arranged in a radiating manner. 
Fig. 21. The blepharoplast. ( b ) in section before it splits to form two rings. A chromatin net- 
work is clearly present in the nucleus. 
Fig. 22. The mature blepharoplast, showing cilia developing from the lower of the two rings. 
Fig. 23. The splitting of the blepharoplast (£), as seen in section, to form two rings. 
Fig. 24. A portion of a blepharoplast, showing the two rings. 
Fig. 25. The two rings of the blepharoplast, seen in section, with cilia attached to the lower. 
Fig. 26. The blepharoplast in section, cilia attached to the lower ring on the right-hand side. 
Fig. 27. A spore-origin with two nuclei and a portion of the blepharoplast ; this would have 
developed into a binucleate zoospore. 
Fig. 28. Base of uninucleate germinating spore, showing remains of blepharoplast ( b ). 
Fig. 29. Base of sporeling containing several nuclei ; the rings of the blepharoplast ( b ) still 
present. 
Fig. 30. Nucleus in germinating spore, showing loose linin network with chromatin granules. 
Fig. 31. Nucleus in germinating spore, showing a possible much-coiled spirem apparently 
connected with a centrosome-like body on the exterior of the nucleus. 
Fig. 32. Metaphase of mitosis in the sporeling, an intranuclear spindle. 
