Reply to comment on 'Structural changes in the rat placenta during the last third of gestation discovered by stereology'

Systemic random sampling which combines both the unbiasedness of random sampling and the efficiency of a systemic sampling, was used in our Research. It is based on the selection of the final sample systematically, while the First sample was selected randomly within the First sampling interval. Sections were sampled at a ratio 1:10 (Section Sampling Fraction - SSF), with a randonm section from the First ten sections and then every 10th section after this initial selection. preliminary mesurements were performed for each of the experimental groups.