Black. — The Morphology of Riccia Frostily Aust. 531 
Fig. 28. Metaphase in the spore mother-cell. The chromosomes are seen as densely staining 
granules. The poles of the spindles are well defined, x 1,500. 
Fig. 29. Telophase. Spindle fibres are distinct only to the equator, which is somewhat 
granular, x 1,500. 
Fig. 30. Formation of the daughter nuclei. Indication of cell plate shown. Spindle fibres 
very distinctly seen, x 1,500. 
PLATE XXXVIII. 
Fig. 31. The cell plate is more distinct than in Fig. 30. x 1,500. 
Fig. 32. The daughter nuclei have moved from the periphery of the spore mother-cell wall, and 
occupy a median position between it and the cell plate. The cell plate appears as a granular line, 
and does not extend entirely across the cell, x 1,500. 
Fig. 33. Metaphase of the daughter nuclei. Spindles are in the same plane. Polar view of 
chromosomes shows the reduced number to be eight, x 1,500. 
Fig. 34. Similar stage to Fig. 33, showing one spindle. The spindle is small and tapers to 
a point at the poles, x 1,500. 
Fig. 35. Formation of the daughter nuclei, x 1,500. 
Fig. 36. Spore tetrad. Nuclei are very small, with the chromatin in one or more lumps, x 1,000. 
Fig. 37. A heavy line is formed inside of the gelatinous layer. This becomes eventually the 
outer spore wall, x 1,000. 
Fig. 38. Inside of the rough spore wall another layer is added. This layer appears striated. 
Contents of cell becoming more granular, x 1,000. 
Fig. 39* Surface view of almost mature spore, showing sculpturing of outer spore coat, x 1,000. 
Spermatogenesis. 
The following drawings were made at table level with a magnification of about 3,000 times : 
Fig. 40. Spermogenous cell with the chromatin clumped together irregularly in the nucleus. 
The nucleus on the whole is denser than the cytoplasm. 
Fig. 41. Two cells in early prophase. The chromatin is seen in a network of irregular lumps. 
Fig. 42. Hollow spireme. The nucleus almost fills the cell. 
Fig. 43. The spireme is segmented and the chromosomes occupy the central part of the nucleus. 
Fig. 44. The nucleus is slightly elongated. 
Fig- 45. The spindles are replacing the nuclear membrane. 
Fig. 46. Similar to Fig. 45. Chromosomes are more distinct. 
Fig. 47. Metaphase. Well-defined spindle with pointed poles. The chromosomes are opposite 
each other at the equator. 
Fig. 48. Stages similar to Fig. 47. 
Figs. 49-51. Polar views of metaphases, showing eight chromosomes, the reduced number. 
The chromosomes are short, curved rods. 
Figs. 52-54. Broad-poled spindles. 
Fig. 55. Telophase. No polar granules observed. 
Fig. 56. Formation of the daughter nuclei. Cell plate is being laid down. 
Fig. 57. The spermogenous cell previous to the last division. 
Fig. 58. The nucleus has elongated, and in the corners of the cells at opposite sides of the 
nucleus are two granules. 
Fig. 59. Similar to Fig. 58. 
Fig. 60. Formation of the spindle fibres. The chromatin is collected in a lump. 
Fig. 61. The oblique spindle, with the chromosomes in the equatorial plate and the spindle 
fibres terminating in the polar granules. 
Fig. 62. Similar to Fig. 61. 
Figs. 63 and 64. Polar views of the oblique division, showing eight short, curved chromosomes. 
Fig. 65. Two diagonal cells with no indication of the polar granules. 
Fig. 66. The diagonal division completed. Sperm cells lying free within the wall of the sperm 
mother-cell. 
Fig. 67. Diagonal cell showing definite body in one of the angles of the cell. 
Fig. 68. Two sperm cells resulting from the oblique division, with the blepharoplasts in the 
same angle of the cell. 
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