i8o 
• Davis . — Nuclear Studies on Pellia . 
Fig. 1 8. Chromosomes at time of prophase, in section showing irregular dis- 
tribution of granules. 
Fig. 19. Daughter-chromosomes pulled apart from the ends. 
Fig. 20. Daughter-chromosomes pulled apart from the middle region. 
Fig. 21. Chromosomes breaking up in the daughter-nucleus after the first 
mitosis. 
PLATE XI. 
Figures 22-35, from germinating spores. 
Fig. 22. Nucleus in spore; synapsis previous to first mitosis; aggregations of 
kinoplasm at one side of nucleus suggests an aster, but is without characteristic 
differentiation. 
Fig. 23. Two asters closely applied to the nucleus, the only example observed 
where such structures were much nearer than 180°. 
Fig. 24. Kinoplasmic differentiation at poles of an elongated nucleus entering 
prophase, as yet scarcely having the characters of asters. 
Fig. 25. Two asters at a distance from the nucleus, the latter not yet in pro- 
phase. 
Fig. 26. Asters developing from aggregations of kinoplasm ; spirem-thread 
segmented. 
Fig. 27. Fibrillae from aster growing around the end of the nucleus. 
Fig. 28. Aster viewed from above, showing insertion of fibrillae in an undifferen- 
tiated centrosphere-like body. 
Fig. 29. Spindle-fibres growing into the nuclear space, centrosphere-like mass 
of kinoplasm at the poles. 
Fig. 30. Spindle-fibres arising from a region of kinoplasm without evidence of 
an aster-like structure. 
Fig. 31. Spindle at metaphase with no trace of aster at the poles, fibrillae 
running into granular kinoplasm. 
Fig. 32. Pole of spindle at metaphase with bushy aggregation of fibrillae. 
Fig. 33- Pole of spindle at anaphase, fibres coming to a point in a region of 
finely granular kinoplasm. 
Fig. 34. Organization of daughter-nuclei, no aster present. 
Fig* 35. Synapsis and prophase of a later mitosis in the germinating spore, 
showing the small asters and delicate radiations in a less amount of kinoplasm. 
Figures 36-40, from seta of a young sporophyte. 
Fig. 36. Arrangement of delicate strands of cytoplasm resembling an aster. 
Fig. 37. Kinoplasm assembling at the ends of the nucleus ; stellate arrangement 
of the cytoplasm ; strands much broader than in Fig. 36. 
Fig. 38. Kinoplasm forming a cap at the poles of the elongated nucleus that 
is entering prophase. 
Fig. 39. Spindle developed from the caps of kinoplasm; chromosomes being 
carried to the nuclear plate. 
Fig. 40. Spindle at metaphase, showing poles formed by convergence of bundles 
of fibres and without a centre. 
