Results of an experiment where two groups of 16 female rats were fed different diets during pregnancy and lactation periods. One group's diet contained a chemical under review, and the other one was a control. For each litter, the number of pups alive at 4 days, and the number of pups weaned (i.e. that survived the 21-day lactation period) were recorded.



A data frame with 32 rows and 3 variables:

[, 1]groupEither control or treated group.
[, 2]iPups weaned.
[, 3]nPups alive at 4 days.


Weil CS. 1970. Selection of the valid number of sampling units and a consideration of their combination in toxicological studies involving reproduction, teratogenesis or carcinogenesis. Food and Cosmetics Toxicology 8: 177-182.