Plate III. 



Fig. 62. — Roof of the segmentation cavity, under strong magnification, drawn 



from a section of the same series as that from which Fig. 53 was 



drawn. Winkel, Oc. 3 x Obj. 5. 

 Fig. 63. — Blastopore region of the same section as Fig. 52, under a higher 



magnification. Winkel, Oc. 3 x Obj. 5. 

 Fig. 64. — Antiblastoporic region of the same section as the last. Winkel, 



Oc. 3 x Obj. 5. 

 Fig. 65. — Blastoporic region drawn from the same sagittal section as Fig. 



54, under a higher magnification. Winkel, Oc. 3 x Obj. 5. 

 Fig. 65'. — Antiblastoporic region of the same section as above. Winkel, 



Oc. 3 x Obj. 5. 

 Fig. 66. — Roof of the archenteron cavity in the section represented in 5S. 



Winkel, Oc. 3 x Obj. 5. 

 Fig. 67 a-e. — Successive stages of Egg No. 1, Group IV., which was punctured 



at the approximate yolk pole. 

 Fig. 68 a-f — Successive stages of Egg No. 2. Group IV., which was punctured 



closely under the left side rim of the first dorsal lip of the blastopore. 

 Fig. 69 a-f. — Successive stages of Egg No. 3, Group IV., which was punctured 



directly above the first dorsal lip of the blastopore on the median line. 

 Fig. 70. a-f — Successive stages of Egg No. 4, Group IV., which was punctured 



on both sides below the first dorsal lip of the blastopore. 

 Fig. 71 a-f. — Successive stages of Egg No. 5, Group IV., which was punctured 



at the approximate middle point of the antiblastoporic region. 

 Fig. 72 ctr-g. — Successive stages of Egg No. 6, Group IV., which was punctured 



closely under the first dorsal lip of the blastopore. 

 Fig. 73 a-f. — Successive stages of Egg No. 7, Group IV., which was punctured 



directly above the middle point of the first dorsal lip of the blastopore. 



