The numbers of spermatozoa found in the perivitelline layer (perivitelline spermatozoa) of hens' eggs during a 14-d period after insemination were found to be log-dose dependent (r = 0.99) on the quantities of spermatozoa inseminated intravaginally in these hens (50, 100, 200 or 400 million/female). 2. Highly significant correlations were also observed between the perivitelline spermatozoa and the proportion of uterovaginal sperm-storage tubules containing spermatozoa on day 14 after insemination. 3. These data confirm that the number of perivitelline spermatozoa in eggs laid on day 2 after artificial insemination (AI) are highly correlated with the mean percentages of fertility of its duration over a 14-d or 24-d period. As a consequence, eggs laid by the 10% highest or the 10% lowest females primarily classified on the basis of this variable exhibited on average 99% or 49.7% fertility, respectively, over a two-week period after AI.