[The importance of environmental factors. 1. Conditions for parasite infection].

Results of research showing an evident influence of the host's species, strain and age on the biology of the parasite have been presented. Various Hymenolepididae and Amidostomum anseris served as models. Irregular growth and development of the parasite in a given host species cannot be used as a sure criterion to determine the quality of the host-parasite system, because this irregularity occurs sometimes in a specific host, too.

[Revision of Fuhrmaniella fausti Tseng Shen, 1932 (author's transl)].

The authors reexamined the original material of Fuhrmaniella fausti recolted by Faust and preserved within the collections of the University of Neuchâtel. They came to the following conclusions: 1. the description of F.