Previous studies, in which morphometric techniques were
used to evaluate luteal development in several species,have
demonstrated that CL undergo dynamic changes in cellular
composition throughout the estrous cycle (4, 8, 10, 11, 36-
38). Basedupon histological observation of mitotic figures, it
has been suggestedthat ovine and bovine luteal cells prolif-
erate only during the early stagesof luteal development, and
that after about day 4 of the estrous cycle, little mitotic
activity is observed (5-7, 39). However, Priedkalns et al. (3)