Pasożytnictwo parateniczne i jego znaczenie w hematologii

The present author gives a definition of paratenic parasitism, and discusses some French, Russian and Polish terms which have hitherto been accepted for determining this form of parasitism. The term proposed by Bear (1952) is considered to be most convenient. The fenomenon of paratenic parasitism has been illustrated by examples of development of some heteroxenous (e. g. Alaria sp., Dipnyllobothrium sp., Spirocerca lupi ) and monoxenous parasites (Toxocara canis, Syngamus traches). It appears frequently to be not an easy matter to distinguish an paratenous host from the conditional intermediate host. It is considered that the latent helmmthoses leading to an inhibition of growth and development of parasites, conneted with the influence of the immune response of the host as well as of the seasons and specific intra-population relationships, are related fenomena to the paratenic parasitism. The author shows a practically considerable importance of the paratenic parasitism, and discusses its value from the theoretical point of view. The discussion deals particularly with the question of the orgin of the fenomenon considered. Is it original or secondary one? Evidence from many sources leads to the conclusion that the paratenic parasitism occuring among the tapeworms and some Nematodes seems to be one the ways leading to the heteroxeny. However, this fenomenon observed among some Nematodes evidences for a disappearance of the parasitism in the intermediate host.