The comparative analysis of the myenteric plexus in pigeon and hen.

Using the thiocholine method and histological techniques the myenteric plexuses of pigeon and hen were studied. Investigations revealed the presence of a nervous network in the wall of the small intestine of both animals. It consists of many nerve fibres crossing each other and creating meshes in a variety of shapes. The density of the network was different according to the species and to the parts of intestine. The myenteric plexus from the pigeon's duodenum is thicker (3.7-fold) than in the remaining part of the small intestine; in the hen this is approximately 2.2-fold thicker. The meshes of the duodenum in both species are smaller than in the jejunum and ileum. The results of histological investigations showed different localization of myenteric plexuses; in pigeon in the space between the circular and longitudinal muscle layers, and in hen within the circular muscle.