This article presents the morphohistological features of the structure of the Duvernois glands in snakes of the Coluber karelini species. It is noted that narrow-shaped snakes, to which the snake of the Coludridae family belongs, belongs to the anteroscopic. According to the morphological structure, the glands are exocrine, which allows this snake to excrete poison directly into the victim, moving along the main duct. Despite a sufficient number of works by both foreign and domestic authors, the question remains open. The results are presented, the corresponding conclusions are drawn. 
Key words: Duvernois glands, Coluber karelini snakes, merocrine type of secretion, poisonous apparatus