The Number of Allantoic Cells in the Chick Embryo

Abstract
Summary: The number of allantoic cells in the chick embryo has been determined for each day of the second week of incubation. Between the eighth and thirteenth day the number rises from 2.3 × 107 to 1.0 × 108. Part of the increase in number of cells per unit area of membrane is by the formation of a second deeper layer of cells. Certain virologic implications of these findings are discussed.