[Antigenic affinity of cestodes in the genus Taenia]. / Antigennoe rodstvo tsestod roda Taenia.

Antigens of four species of the genus Taenia (T. ovis ovis, T. ovis krabbei, T. hydatigena and T. parenchimatosa) were studied by means of immunodiffusion reaction in agar gel with the use of hyperimmune sera. It has been established that extracts of the studied cestodes contain a great number of antigens, which during parenteral administration cause a synthesis of antibodies in rabbits. In homologous systems the number of recorded antigen-antibody complexes varied from 5 to 10. The most close antigenic affinity was found between T. ovis ovis and T. ovis krabbei, T. ovis ovis and T. hydatigena, as far as the main mass of precipitation bands in the immunodiffusion reaction fused together that suggests the identity of corresponding antigenic components. In all cases when analysing antiserum to T. parenchimatosa extract no differences of species-specific character in heterologous systems were traced.

[Embryonic development of Taenia pisiformis and T. hydatigena (Cestoidea, Cyclophyllidea)]. / Embrional'noe razvitie Taenia pisiformis i T. hydatigena (Cestoidea, Cyclophyllidea).

A description of the consecutive stages of ripening of ovary cells of early fission and gastrulation of T. pisiformis and T. hydatigena, peculiar to the common type of fission of Cyclophyllidea is given. The fission has signs of double spiral fission which takes place in primitive Turbellaria. The primitiveness of early embryogenesis is reflected in early determination of macromeres, in the absence of strict regulation in the location of blastomeres, in the formation of blastula and unipolar gastrulation with the absence of morphological differentiation of ectoderm and mesenchyme.

[Chromosomal apparatus of trematodes of the general Diplostomum and Tylodelphys (Strigeidida, Diplostomatidae) and its taxonomic significance]. / Khromosomnyi apparat trematod rodov Dilostomum i Tylodelphys (Strigeidida, Diplostomatidae) i ego taksonomicheskaia znachimost'.

The chromosomal apparatus of three species of trematodes of Diplostomum (D. spathaceum, D. indistinctum, D. mergi) and one species Tylodelphys (T. clavata) is described. It has been suggested that karyological investigations can be used for taxonomic purposes. The opinion has been expressed that the number of chromosomes in the karyotype of these trematodes plays no taxonomic role. Of great taxonomic significance are the size and morphology of chromosomes. Differences in karyotypes of trematodes belonging to different species and genera were revealed by these characters. The absence of close dependence between morphology of adult and specific peculiarities of karyotypes in species of the same genus enables in some cases the use of chromosomal apparatus as a most reliable criterion for a differentiation of close species.