126 Bristol . — Life-history and Cytology of Chlorochytrium grande. 
PLATE VI. 
Figs. 21-30. Sections showing nuclei and nuclear division preparatory to the formation of 
aplanospores. x 1,435. 
Figs. 21-23. Resting nuclei with surrounding cytoplasm, showing variations in karyosome and 
nuclear network. 
Fig. 24. Resting nucleus with three karyosomes. 
Fig. 25. Cell in which the cytoplasm has become vacuolated and the karyosome of the nucleus 
has broken up into numerous granules. 
Fig. 26. Beginning of spireme formation ; granules collecting together to form a continuous 
thread. 
Fig. 27. Spireme stage of nuclear division. 
Fig. 28. Nucleus with spireme cleft longitudinally. 
Fig. 29. Cell containing probably thirty-two dividing nuclei, a, chromosomes upon an equa- 
torial plate ; b and c, successive stages in passing of chromosomes to opposite poles of the spindle. 
Fig. 30. Cell containing probably 128 dividing nuclei, d and e , further stages in passing of 
chromosomes to poles of spindle; f, crowding together of chromosomes preparatory to reconstruction 
of daughter-nuclei, p. pyrenoid ; f.p. fragmenting pyrenoid. Cell-wall omitted. 
Figs. 31-34. Formation and development of aplanospores. x 535. 
Fig. 31. Cell in which simultaneous division of the contents into a number of aplanospores has 
just taken place. 
Fig. 32. Aplanospores developing inside the old wall of the mother-cell, the inner layer of 
which has disintegrated to form a mucilaginous mass. Each aplanospore has acquired a cell-wall. 
Fig. 33. Cluster of cells at different stages of development, set free by the complete dissolution 
of the mother-cell wall. 
Fig. 34. Cytology of the developing aplanospore shown by means of stained sections, a and b } 
median sections of very young cells with simple lobed chloroplast surrounding the nucleus ; c , non 
median section of a rather older cell with two pyrenoids. 
