00643cam a22002051 4500 agr22000104 DLC 20260227110942.0 800910s1921 enk 000 0 eng agr22000104 (OCoLC)6696888 DLC AzTeS DLC premarc QH471 .P4 Pell, Charles Edward. The law of births and deaths. Being a study of the variation in the degree of animal fertility under the influence of the environment. By Charles Edward Pell. London, T. F. Unwin, ltd. [1921] 192 p. 23 cm. Fertility. 8772 8772