Fig. 1. Embryonic (A) and yolk (B) mass for the three experimental groups: normoxia N21 (white bars), 15%O₂ H15 (grey bars) and 10%O₂ H10 (black bars). ^*Significant differences between the incubation groups at a given age; significant differences in mass compared to all preceding incubation ages. Values are means ± S.E.M. For N values, see Table 1.