810 
DR. E. B. WILSON ON THE DEVELOPMENT OF RENILLA. 
sixteen spheres. Time:—Fig. 42, 9.20 a.m. ; 43, same in different 
position ; 44, thirty m. X G5. 
Figs. 45 to 48. Segmentation of an egg which first divided incompletely into eight 
spheres, and afterwards completely into sixteen. Time:—Fig. 45, 
9.5 a.m. ; 46, five m.; 47, twenty-one m.; 48, thirty-three m. X 65. 
Figs. 49 to 58. Segmentation of an egg which first divided irregularly and incom¬ 
pletely into eight. The sphere marked a failed to divide with the others 
at the third cleavage but divided at the fourth (57). Time :—Fig. 49, 
10.29 a.m. ; 50, four m.; 51, six m.; 52, fifteen m.; 53, different position, 
seventeen in.; 54, thirty-one m.; 55, forty-one m. ; 56, forty-eight m.; 
57, fifty-six in.; 58, sixty-eight m. X 65. 
Figs. 59 to 62. “ Partial ” or progressive form of segmentation. Time :—Fig. 59, 
10.6 a.m. ; 60, eight m. ; 61, nineteen m.; 62, same in different position. 
X 65. 
Figs. 63 to 67. Segmentation similar to the last. Time:—Fig. 63, 11.35 a.m.; 
64, nine m.; 65, thirteen m.; 66, nineteen m.; 67, twenty-one m. X 65. 
PLATE 54. 
Figs. 68 to 72. Very unequal and irregular form of segmentation. Time :—Not 
recorded. X 65. 
Figs. 73 to 76. Segmentation of Leptogorgia. Time:—Fig. 73, 10.14 a.m.; 74, 
three m.; 75, twenty-one m.; 76, thirty-six m. X70. 
Figs. 77 to 85. Further segmentation of Leptogorgia', another specimen. Time:— 
Fig. 77, 10.5 a.m. ; 78, fifteen m. ; 79, twenty-four m.; 80, thirty-five m.; 
81, seventy-eight m.; 82, ninety-five m.; 83, one h. fifty-five m.; 84, two h. 
five m.; 85, two h. twenty-five m. X 70. 
Fig. 86. Section through unfertilised egg showing germinal vesicle and spot, d. X85. 
Fig. 87. Section through egg immediately before segmentation. X85. 
Fig. 88. Section through the same egg, separated from the last section by three 
intervening ones. X85. 
Fig. 89. Section through an egg in the act of division into sixteen spheres, directly 
from the unfertilised egg. X85. 
Fig. 90. Section through an egg which from the exterior appeared to consist of eight 
spheres. X 85. 
Fig. 91. Section through an egg with sixteen superficial spheres and a central 
unsegmented mass. X85. 
Fig. 92. Similar to the last but with the central mass much reduced. X 85. 
Fig. 93. The spheres now extend to the centre of the egg and the central mass has 
nearly vanished. X 85. 
