RESUMEN
The communication substantiates the opinion that the theory of natural nidality of plague; which is based on the fundamental recognition that fleas play a leading role in the transmission and accumulation of the plague pathogen, cannot be disproved or substantially changed on the alternative weakly reasoned assumptions and hypotheses. All its "bottlenecks" are quite understandable when considering the long-term volumetric materials that have been gathered directly in nature and generalized in multiple publications. Plague is an obligate transmissive infection; its, agent is a highly specialized parasite that is completely associated in its vital activity with the only group of the blood-sucking insects--fleas and that is transmitted through periodic colonization of warm-blooded animals for a short time. All other types of plague microbe persistence in nature are either occasional or minor and do not play any significant role in pathogen persistence in the natural foci of this disease. There are no strong grounds for seriously considering the attempts to revise the main points of the theory of natural nidality of plague, which are widely held in current academic publications.