236 BUNTING. 
EXPLANATION OF PLATE IIT. 
[Figs. 48-57, 62, 63 X 187. 58-67 (with exception of 62, 63) X 94.] 
Fic. 48. Section of blastula when about sixteen cells. 
Fic. 49. Tenth section of a series of twenty-five. 
Fic. 50. Twelfth section of same series. 
~ 
Fic. 51. Section showing continued multipolar delamination of ectoderm 
cells to form endoderm. (Embryo about 2 hrs. 40 min. old.) 
Fic. 52. Section of embryo about the same age, but further developed. 
Multipolar delamination. Division of endoderm cells. 
Fic. 53. Next section in same series, showing an elongated cell, a, delami- 
nating. 
Fic. 54. Sixteenth section of series of thirty-nine. Continued multipolar 
delamination. Elongated cell, 6. Division of endoderm cells. 
Fic. 55. Seventeenth section of same series, showing elongated cell, 4, with 
karyokinetic figure. 
Fic. 56. Sixteenth section, series of thirty-three. Embryo consisting of solid 
mass of cells. (About 3 hrs. 30 min.) 
Fic. 57. Cross-section of planula (23 hrs.). Formation of coelenteric cavity. 
Fic. 58. Longitudinal section of attached planula. (41% days.) Coelenteric 
cavity closed. 
Fic. 59. Section of young hydroid. (5 days.) Coelenteric cavity closed. 
Appearance of two tentacles. 
Fic. 60. Section of young hydroid. (About 5 days.) Hydrorhiza, 2. 
Fic. 61. Section of same hydroid, showing mouth. 
Fic. 62. Section of half embryo. Karyokinetic figure, 2. 
Fic. 63. Cross-section of half embryo. Breaking down of endoderm to form 
coelenteric cavity. 
Fic. 64. Outline drawing of hydroid about six days old, 3 mm. high (from 
life). Stolon-like growth at point of attachment. Appearance of two tentacles. 
Fic.65. Outline drawing of hydroid about one week old (from life), viewed 
from above, showing hydrorhiza, tentacles, and mouth. 
Fic. 66. Outline drawing of hydroid about five days old (from preparation). 
Six tentacles. Hydrorhiza at one point turning up as though to form hydroid. 
Fic. 67. Outline drawing of hydroid, nine days old (sketch from life). Bud- 
ding of hydrorhiza to form reproductive hydroid. 
Fic. 68. Medusa of Podocoryne (drawn from life by R. Takano). 
