Ultrastructure of sensory nerve terminals in the penis in green monkey (Cercopithecus aethiops sabaeus).

Tje paper describes the ultrastructure of axons in the endings of various types from the corium in the glans penis in green monkey. In the Meissner's endings the axons are mostly completely enveloped in the plasma of Schwann cells. They contain numerous mitochondria which are partially vacuolated or are quite converted into vacuoles. Next, there are pseudomyelinated figures, light vesicles and further organelles. In the papillar simple glomerular endings with accumulation of Schwann cells there are axons irregular in shape, eccentrically placed in the plasma of Schwann cell, rounded smaller axons either completely or partially surrounded by the plasma of Schwann cell and finally axons with a concentric system of lamellae up to four in number, In the complicated glomerular endings the axons vary in appearance and are enveloped in one to five lamellae of Schwann cells, which is typical of those formations. About some of these systems there is a sign of a capsule formed by an elongated lamella probably of the perineurium. When the axons are not enveloped in the plasma of Schwann cell, they are covered by the basement membrane. In close neighbourhood of the epidermis so-called free endings forming groups were found. The plasma of Schwann cell covers them either partially or completely or it again forms around them a lamellar system amounting up to four layers. It is noticeable that these axons are very poor in organelles. A comparison of the simple sensory corpuscles in the nose skin in hedgehog, the funtional properties of Meissner's endings and the simple corpuscles results in the view that the complexes having a larger amount of lamellae correspond to an extent to the simple sensory corpuscles ant that the Meissner's endings and the complicated glomerules are probably a morphological and functional equivalent of simple sensory corpuscles in the non-primate mammals and that the gloverular endings may also be the first (developmental) stage of the simple sensory corpuscles.