ABSTRACT
This paper deals with the development of Paragonimus westermani (Kerbert, 1878) in mice inoculated with metacercariae or stunted adolescariae. In metacercaria-inoculated mice, all worms were stunted all the time, but when the stunted worms were orally transferred Into mice, some (8.4%) grew so fast that their rudimentory reproductive organs appeared and their length was over 3 times that of stunted worms 3 weeks post inoculation; while 91.6% of the recovered adolescariae were still stunted and morphologically similar to excysted metacercaiae. When the stunted worms were repeatedly transferred through mice by oral route 8.2-10.1% of the recovered worms developed quickly, while the remainder was still stunted (Table 1).After 3 transfers in mice, the stunted worms were still able to infect dogs orally and reach maturity (Table 2).On the basis of the study, it is postulated that cannibalism and preying among wild rats would enable P. westermani to be transferred among rodent paratenic hosts.