in the Hymenomycetes . 
5i3 
spindle-figure. At the poles of the spindle are two deeply stained dots (cen- 
trosomes?). The nucleolus is still visible, but is much less prominent than 
before. 
Fig. 10. Transverse section of basidium in same stage of development as 
Fi g- 9 - 
Fig. 11. Basidium with chromosomes, which are beginning to separate into two 
groups. The nucleolus is still visible, but is very small and faintly coloured. 
Fig. 12. Transverse section of basidium at the stage figured in 11. 
Fig. 13. Later stage in the separation of the two groups of chromosomes. The 
basidium was slightly oblique ; the lower part was out of focus. 
Fig. 14. Stage in which the chromosomes, having reached the poles of the 
spindle, begin to fuse together. 
Fig. 15. Fusion of chromosomes at the poles of the spindle into bright red, 
irregular masses, around which the new nuclear membranes form. 
Fig. 16. Transverse section of basidium, at slightly later stage than that 
figured in 15. 
Fig. 1 7. Basidium with two daughter-nuclei just formed. The nuclear 
membrane is distinctly visible, but not the nuclear network. 
Fig. 18. Transverse section of basidium, with two daughter-nuclei, at a slightly 
earlier stage perhaps than Fig. 1 7. 
Fig. 19. Basidium with two completely formed daughter-nuclei. They have 
now the same structure as the parent nucleus. 
Fig. 20. Basidium with the two daughter-nuclei just beginning to undergo 
changes previous to division. The chromosomes are shown, beginning to ac- 
cumulate at the apex of each nucleus. 
Fig. 21. Oblique section of a basidium, showing one of the daughter-nuclei, 
with a group of deeply stained bright red chromosomes. 
Fig. 22. Basidium, drawn at two different levels to show the two dividing 
daughter-nuclei. In each can be seen a spindle-figure with deeply stained dots at 
each pole. 
Fig. 23. Transverse section of a basidium, at a later stage than Fig. 22. Com- 
plete separation of the chromosomes has taken place. The nucleoli can still 
be made out, but are very small. 
Fig. 24. Basidium with four completely formed nuclei, just after the division of 
the two daughter-nuclei has taken place. 
Fig. 25. Basidium showing sterigmata just beginning to develop. 
Fig. 26. Slightly later stage than Fig. 25. The four nuclei have made their way 
towards the base of the basidium, previously to their coalescence with each other. 
Fig. 27. Stage in which the four nuclei are shown combining together. 
Fig. 28. Appearance of the four nuclei at a slightly later stage. They are 
now in such close combination with one another, that the outlines of the individual 
nuclei cannot be made out. 
Fig. 29. Basidium, with a young spore attached to one of the sterigmata (the 
others having fallen off), showing the nuclei beginning to separate again. They 
are very irregular in outline and the nuclear membrane appears very thick. 
Fig. 30. Basidium at a stage when the spores are fully formed. The nuclei 
are found at the bases of the sterigmata, ready to make their way into the spores. 
The structure of the nuclei at this stage appears to be quite normal. 
