Pl. KK. 
HUBRECHT. 
Fig. 52. Longitudinal section of a Tarsius embryonic shield in whieh at 
the spot where the protochordal wedge pw has proliferated downwards a rudimen- 
tary attempt at a blastoporic perforation has quite exceptionally arisen. Pp proto- 
chordal plate, pw protochordal wedge, wz ventral mesoblast, #7 umbilical vesicle. 
ec embryonic ectoderm; mes mesoblast, springing from protochordal plate. — 
Fig. 53. The early evanescent blastopore /é) of the hedgehog (after Hubrecht, 
02). — Fig. 54. The same of the mole (after Heape); 2 blastopore, ez entoderm. 
