47 % Ferguson . — The Development of the Egg and 
PLATE XXV. 
Fig. 58. The spindle fully established ; the two chromatic spirems still perfectly 
distinct, x 540. 
Fig. 59. The two spirems after segmentation ; the two halves of the spindle 
seem to indicate the maternal and the paternal portions of the mitotic figure, 
x 540. 
Fig. 60. Early stage in the formation of the chromosomes. The chromatic 
elements still occur in two distinct groups, x 540. 
Fig. 61. The chromosomes being oriented at the nuclear plate. The distinction 
between paternal and maternal elements no longer evident, x 540. 
Fig. 62. A cross-section through the nuclear plate just before the splitting of 
the chromosomes ; twenty-four segments are distinctly shown, x 540. 
Figs. 63-65. Some of the aspects presented by this mitotic figure during meta- 
kinesis. x 540. 
Fig. 66. An anaphase of the mitosis. . 
Fig. 67. A late anaphase of the division ; the poles terminate in granular areas 
from which delicate threads extend into the cytoplasm ; some of the nucleolar 
substance from the egg-nucleus still persists, x 540. 
Fig. 68. One end of a spindle in the same stage as the above ; the fibres which 
radiate from the polar region of the spindle are very abundant and stain deeply, 
x 540. 
Fig. 69. One aspect presented by the karyokinetic figure in the telophase of this 
division, x 540. 
Fig. 70. The two segmentation-nuclei fully formed, x 540. 
Fig. 71. One of the two segmentation-nuclei in an early prophase of division, 
x 540. 
Figs. 72-73 b. Later stages in the second division, showing two chromatic 
spirems. x 540. 
Fig. 74. A still later stage, x 540. 
Fig. 75. An entire archegonium showing the position of the two segmentation- 
nuclei during division, x 70. 
Fig. 76. An archegonium showing the original position of the four segmentation- 
nuclei. x 70. 
Fig. 77. The same after the nuclei have begun their downward movement, x 70. 
Fig. 78. The same after the nuclei have almost reached the base of the oosphere. 
x 70. 
Fig. 78 b. A portion of number 78, showing details in nuclear structure, and 
fibres in the surrounding cytoplasm, x 540. 
Fig. 79. The lower part of an archegonium after the four nuclei have arranged 
themselves at the * organic apex ’ of the oosphere. x 70. 
Fig. 79 b. A portion of the above ; the nucleus is in the early prophase of 
division ; the cytoplasm surrounding the nucleus has become dense and deeply 
staining, x 540. 
Fig. 80. The basal portion of an egg ; the four segmentation-nuclei are in a 
metaphase of the mitosis, x 70. 
Fig. 80 b. A part of the same showing details, x 540, 
