title: [Certain principles of the secondary simplication of the life cycles of helminths].
abstract: On the basis of the analysis of regularities accompanying the secondary simplification of the life cycles of helminths on account of the reduction in the number of the animals-hosts 8 rules have been formulated. They are based on the following important regularities. 1. At the secondary simplification of the life cycles of helminths never fall out the first intermediate host in Trematoda and the definitive host in Nematoda. This phenomenon is suggested to be called "the host stability in the life cycle". 2. Mostly often from the life cycles fall secondarily out those hosts which join in the life cycle at its first complication later. 3. The phase of the helminth having transformed into a parasitic form at the first complication of its life cycle remains the same at the secondary simplification of this cycle.
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D006376:Helminths / Q000502:physiology*
vernacular_title: O nekotorykh zakonomernostiakh pri vtorichnom uproshchenii zhiznennykh tsiklov gel'mintov