Sensitive innervation of the copulatory organ in Struthio camelus: comparison to the corresponding district in female proctodeum.

The AA. have studied the nerve component of male copulatory organ and ventral part of female proctodeum in the ostrich. This paper represents the concluding part of the plan of research that aimed to verify some data and hypothesis referred in previous observations. The innervation of the considered districts was always constituted by autonomic and sensitive somatic nerve components. The autonomic innervation was represented by isolated and grouped ganglion cells located along the course of nerve bundles or in the point where different nerve bundles converged. This nerve component was frequently in close connection with the blood vessels. The sensitive somatic innervation was constituted by free and capsulated nerve endings. The latter, always supplied by a typical structure and morphologically classified as Pacini, Pacini-like and genital's corpuscles, could be found either isolated or grouped within the different layers of both the examined anatomical territories. The grouped corpuscles, in particular Pacini's corpuscles, could organize simple and complex flower sprays, opposito-polar corpuscles and poikilomorphous fibres. For the first time the capsule's lamellar organization in Pacini's corpuscles in Birds was documented by means of light microscope. The occurrence of genital corpuscles seemed to be exclusive in the ventral part of female ostrich proctodeum, corresponding to the male site in which lies the copulatory organ.