Fig. 4
From: The development of the oviducal gland in the Rajid thornback ray, Raja clavata
Brown material accumulations. a Deep recesses of the baffle zone in a developing female. H&E. b Detail of the brown material observed in the baffle zone in a developing female. H&E. c Terminal zone in an actively spawning female. H&E. d Detail of the brown material observed in the terminal zone in an actively spawning female. BM brown material, ST secretory tubules, BV blood vessel, ML muscle layer, CT connective tissue, MST mucous secretory tubule, SST serous secretory tubule