Figure 3 in Diversity and evolution of sexually dimorphic mental and lateral glands in Cophomantini treefrogs (Anura: Hylidae: Hylinae)

Figure 3. Light micrographs of cross sections of the mental skin region of some species of Cophomantini: A, Hypsiboas pulchellus (). B, Hypsiboas pulchellus (). C, Hypsiboas benitezi (). D, Hypsiboas benitezi (). E, Aplastodiscus leucopygius (). F, Aplastodiscus leucopygius (). G, H, Hyloscirtus palmeri (). I, Hyloscirtus palmeri (). J, Hypsiboas faber (). K, Hypsiboas faber (). L, Aplastodiscus eugenioi (). M, Hyloscirtus caucanus (). N, Hypsiboas heilprini (). O, Bokermannohyla saxicola (). A, B, C, D, E, F, G, H, I, J, K, comparative sections between males and females. A, B, There are no distinguishable differences between males and females; only ordinary mucous glands (OMGs) and ordinary serous gland (OSGs) can be recognized in both sexes. C, E, L, sexually dimorphic skin glands (SDSGs) are closely packed with their secretory portion in a single layer, and specialized mucous glands (SMGs) are of the alveolar type. Specialized serous glands (SSGs) are present in (E) and (L) but are absent in (C). Note in (L) the lack of differences in the thickness of stratum spongiosum (ss) in the mental gland region in comparison with surrounding region. Also, some SMGs are scattered out of the region of higher glandular density. G, H, the mental gland has a notorious thickening of the ss and a reduction of stratum compactum. SMGs of tubuloalveolar morphology are closely packed with their secretory portion in a single layer. Note the absence of SSGs and OSGs. J, N, mental glands are characterized by the disposition of the secretory portion of different glands in two layers, SMGs of the tubuloalveolar morphology, and the occurrence of SSGs. Note the differences in thickness of the ss in (N). M, O, both glands are characterized by the presence of scattered SDSG but, although they are of the mucous type in (M), they are of the serous type in (O). Histological staining: A, B, K, Masson–Goldner's trichrome; G, I, J, N, Masson's thricrome; C, D, H, L, M, Alcian blue-periodic acid Schiff; E, F, semithin sections after toluidine blue-basic fuchsin stain; (O) Sudan black B. sc, stratum compactum; ss, stratum xspongiosum. Note limits of sc and ss within arrows. Scale bars = 100 μm.