Dr. Murai Éva szerk.: Parasitologia Hungarica 22. (Budapest, 1989)

The leading part in parasitocenology belongs to "microparasitocenosis"

. All other parasitic ecosystems represent either its subsystems of different constructive range or systems of the highest level where microparasitocenosis is an indispensable initial component. It should be emphasized once more that events in these systems differ radically from those taking place in microparasitocenosis. The investigation of parasitic ecosystems of every level is carried out by studying the structure, ways and regularities of function of their separate compounds. Dismembering parasitocenosis into its structural components for investigation meets the demands of scientific methodology. Having studied contradictory parts of one or other object of nature one is able to find ways to their dialectic unity in order to perceive a studied object in its natural integrity and concreteness

. It is clear that while studying an object analytically we are not to overlook its real Integrity and we should respectively direct our research guided by a single plan and methodology. Modern medical and veterinary practice reveals the failing attempts to cover by parasitocenologic investigations the whole species composition of microparasitocenosis of man and domestic animals, in whom it is particularly rich. That Is why, in case of need, one has to limit investigations of the above-mentioned hosts to the study of separate members of parasitocenosis, analysing interactions of the pathogens directly responsible for the rise and development of concurrent parasitoses. Interests of the theory of parasitocenology and of medical, veterinary and phytopathological practice require to investigate écologie associations of free-living generations of pathogenic agents in a parasitocenogenic ecosystem at the same level as the study of their activity within the host. This is needed for an objective solution of landscape epidemiology problems, for studying ways of circulation of free-living stages of parasites In external environment and for elucidation of mechanisms of their transmission from an infecting host (donor) to an infected one (recipient). As scientific facts are being accumulated, integration parallels differentiation of parasitologic knowledge. Thus today one can already distinguish the division of parasitocenology according to the objects of research into medical, veterinary and Phytopathologie branches. The tendency of dismembering general parasitocenology according to the type of environment into hydroparasitocenology and geoparasitocenology with their special methodology and trends becomes more and more perceptible. General parasitocenology as a theoretic subject is regarded as fundamental science, and its branches dealing with theoretical topics applied to medical, veterinary and phytopathological practical needs are therefore drawn towards applied sciences. They all are guided by a single methodology, common principles of Inductive logic; they use both specific methods and methods of the theory of probability. The extreme complexity of the purposes of parasitocenology does not hinder the development of complex cognition methods of objective laws of life and those of the development of parasitic ecosystems. A prospective policy in this direction comprises elucidation of all the variety of Interactions and interrelationships among écologie groups of parasites, a search for factors defining structure and integral functions of parasitocenoses, and the demonstration of all aspects of relations in host-parasite systems that developed In the course of their common evolution.