“…The corpus luteum increases from 8 irnn^ at 1 day after estrus to 20.5 at 18 days and decreases to 12.5 mra3 at the following estrus. In the event of preg nancy the corpus luteum persists without any change in size for the dur ation of pregnancy (Asdell, 1946;Catchpole, 1959). Bowerman and Melampy (1962) observed a gradual increase in corpus luteum weight from 4,3 g during the first 50 days to 7.4 g at 210 to 250 days of pregnancy and a decrease to 6.2 g at 250 to 280 days.…”