The foot pads of five rodents were studied by means of gross morphology and histology. The secretory portions of the glands are placed caudad to the openings of the ducts in species that mostly walk on the ground. This way the secretions are pressed out during walking by rolling on the foot pads craniad. In climbing species, the secretory portions are placed underneath the openings of the ducts and lead to secretion delivery during climbing by grasping. With their small and flat pads with few glands, digging species have a rather smooth and dry volar aspect to work in a shovel-like way. In contrast, climbing species have large and soft foot pads with a lot of glands. The thickness of the cornified layer is positively correlated with the density of glands and increases strikingly from digging to climbing species. Although scent production is possible for these glands, this points to a function of the secretions in connection with the cornified layer. In climbing species, the secretions of glands can moisten the skin and thereby heighten the friction between volar and climbing surface to prevent the animal from slipping. The density of glands per unit of surface is doubled in the ridged skin of Muscardinus avellanarius in comparison with the coned skin in Micromys minutus. While M. minutus mainly climbs by grasping stalks of reed and can tighten the grip by increasing the grasping force, M. avellanarius often climbs by pressing the volar aspect on to the bark, whereby friction is increased by the moistened skin.

Schistosome cercariae of the genus Trichobilharzia are the causative agent of swimmers' itch. In order to characterize the changes in parasites during and after the penetration of the host skin, in vitro and in vivo (in ducks and mice) transformations of T. szidati cercariae to schistosomula were performed. Ultrastructural observation revealed that cercariae possess a simple outer tegumental membrane with a thick glycocalyx. As with human schistosomes, the latter structure disappears during transformation and a new double membrane with putative protective function is formed. Our biochemical and immunological observations showed that the carbohydrate-rich glycocalyx of cercariae is readily bound by lectins and antibodies. The in vitro transformation to schistosomula can be detected by enhanced reactivity of 2 lectin probes (PNA and ConA) with the surface. The in vivo-transformed (skin and lung) schistosomula appear to have few surface ligands for the 12 lectin probes being tested. Similarly, the cercarial surface and its remnants on the in vitro-produced schistosomula is recognized by sera from immunized mice and humans with cercarial dermatitis; the tissue schistosomula fail to react with these antibodies. The loss of surface targets as a part of parasite immune evasion within the host is discussed.