“…The present histochemical studies agree well with biochemical studies on the secretion of progesterone and 20a-hydroxypregn-4-en-3-one (20a-OH-P) (Eto, Masuda, Suzuki & Hosi, 1962;Telegdy & Endroczi, 1963;Fajer & Barraclough, 1967;Yoshinaga, Grieves & Short, 1967;Hashimoto, Henricks, Anderson & Melampy, 1968;Chatterton, Macdonald & Greep, 1968;Hashi¬ moto & Wiest, 1969;Uchida, Masumikado & Tamotsu, 1969;Roser & Bloch, 1972). The diffuse lipoproteins are presumed to derive from the abundant membranes of smooth reticulum, act as a site for enzymes involved in steroidogenesis and may also serve as a reservoir for the storage of hormone precursors (Flint & Armstrong, 1972;Armstrong & Flint, 1973).…”