Plate IV. 



Fig. 74 a-f. — Successive stages of Egg No. 9, Group IV., which was 

 punctured at the upper pole. 



Fig. 75 a-f. — Successive stages of Egg No. 10, Group IV., which was 

 punctured at the sub-antiblastoporic region. 



Fig?. 76-84. Diagrammatic representations of the results obtain- 

 ed from Eggs Nos. 1, 2, 3, 4, 5, 6, 7, 9, 10, Group IV., in regard 

 to the location of the embryonic body and the punctured region of 

 every egg. The curved line above the egg-equator, in every figure, 

 is the lower limit of the early area of the segmentation cavity, 

 while the dotted line denotes the future lip of the blastopore. 



Fig. 76. — Diagram of Egg No. 1, Group IV., Figs. 67 a-e. 



Fig. 77.— Diagram of Egg No. 2, Group IV., Figs. 68 a-f. 



Fig. 78.— Diagram of Egg No. 3, Group IV., Figs. 69 a-f. 



Fig. 79.— Diagram of Egg No. 4, Group IV., Figs. 70 a-f. 



Fig. 80. — Diagram of Egg No. 5, Group IV., Figs. 71 a-f. 



Fig. 81. — Diagram of Egg No. 6, Group IV., Figs. 72 a-g. 



Fig. 82.— Diagram of Egg No. 7, Group IV., Figs. 73 a-f. 



Fig. 83.— Diagram of Egg No. 9, Group IV., Figs. 74 a-f. 



Fig. 84. — Diagram of Egg No. 10, Group IV., Figs. 75 a-f. 



Fig. 85 a-c. — Successive stages of Egg No. 4, Group I. 



Fig. 85'. — Diagrammatic representation of the results obtained from the 

 above egg. 



Fig. 86 a-c. — Successive stages of Egg No. 5, Group I. 



Fig. 86'. — Diagrammatic representation of the results obtained from the 

 above egg. 



Fig. 87 a-d. — Successive stages of Egg No. 1, Group II. 



Fig. 88. — Diagrammatic representation of the results obtained from the 

 above egg. 



Fig. 89 a-e. — Successive stages of Egg No. 4, Group II. 



Fig. 90. — Diagrammatic representation of the results obtained from the 

 above egg. 



Fig. 91 a-d. — Successive stages of Egg No. 9, Group II. 



Fig. 92. — Diagrammatic representation of the results obtained from the 

 above egg. 



Fig. 93 a-h. — Successive stages of Egg No. 3, Group III. 



Fig. 94. — Diagrammatic representation of the results obtained from the 

 above egg. 



Fig. 95 a-g. — Successive stages of Egg No. 4, Group III. 



Fig. 96. — Diagrammatic representation of the results obtained from the 

 above egg. 



