Oysters spawn when ripe, with rising temperatures that may or may not reach 20 °C. and at times not determined by lunar cycles. The growth of the larva to the ultimate size, height 365 μ, at temperatures of 19, 20 and 21 °C., requires 30, 26 and 24 days respectively. The growth curves developed, not sigmoidal in shape, have been used to predict spatfall maxima.