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107 cells, Carnegie No. 8663.

• Described by Hertig et al. (1954). Uterine.
• No zona pellucida (fig. 8). Diameter, 153 x 115 μm (103 x 80 after fixation; 91.6 x 83.3 after section- ing); diameters of blastomeres varied from 8 to 21.
• Large blastocystic cavity (58 μm). Embryonic mass composed of 8 cells: epiblastic, hypoblastic, and a presumed primordial germ cell (Hertig, 1968).
• Believed to be about 41⁄2 days old. Khvatov (1967), without further elaboration, claimed: “according to photographs, should be of the male sex.” Smith (1970, fig. 15), without further justification, claimed that a cytoplasmic vac- uole was “the first indication toward an amniotic space.”