810 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
Figs. 
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. X65. 
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-threem. X65. 
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 m.; 54, thirty-one m.; 55, forty-one m.; 56, forty-eight m.; 
57, fifty-six m.; 58, sixty-eight m. X 65. 
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. 
<< (35 
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. X65. 
PLATE 54. 
68 to 72. Very unequal and irregular form of segmentation. Time :—Not 
recorded. X65. 
73 to 76. Segmentation of Leptogorgia. Time:—Fig. 73, 10.14 am; 74, 
three m.; 75, twenty-one m.; 76, thirty-six m. X70. 
gs. 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. X70. 
. Section through unfertilised egg showing germinal vesicle and spot, d. X85. 
. Section through egg immediately before segmentation. X 85. 
. Section through the same egg, separated from the last section by three 
intervening ones. X85. 
. Section through an egg in the act of division into sixteen spheres, directly 
from the unfertilised egg, x 85. 
. Section through an egg which from the exterior appeared to consist of eight 
spheres. X85. 
. Section through an egg with sixteen superficial spheres and a central 
unsegmented mass. X85. 
. Similar to the last but with the central mass much reduced. 85. 
. The spheres now extend to the centre of the egg and the central mass has 
nearly vanished. X85. 
