Acta Zoologica Academiae Scientiarum Hungaricae

151쪽

Acta Mologica Academiae Scientiarum Hungaricae 22, 2976

152쪽

Acta Mologiea Academiae Scientiarum Hungiarieae 22, I976

153쪽

Aeta MoIoglea Academiae Scientiarum Hungarieae 22, 2976

154쪽

Aeta Mologica Academiae Scientiarum Hungarieae 22, I976

155쪽

Acta Mologica Academiae Scientiarum Hungaricae 22, I976

156쪽

Acta Mologica Academiae Scientiarum Hungarieae 22, 1976

157쪽

Aeta MoImica Aeademiae Scientiarum Hungarieae 22, 1976

158쪽

scheint.

MESCH.

Acta Mologica Academiae Seientiarum Hungarieae 22, I976

159쪽

Acta Zoologica Academiae Scientiarum Hungaricae 22, 1976

160쪽

XXII. 1 2 19 6 p. 155 163

Analysis of cases of symmetrical and asymmetrical duplication os the male andia inale median regioris in the reproductive systems in systematically unrela ted species indicates the existence of a single pair of male genital primordia in somite XI, similario the feniale genital primordia in XII. The male pair provides the patred male ducis and serialty repetitive interso mital testes. In developinent, the primordia evocate the formation of the genital burga and pore and organiZe the median region.

Embryological studies have shown the developnient of the feniale genitalprimordia froni the oleavage of a single celi in XII, the 1 male gomite. Division of this celi provides a pair of gono blast celi S. These Separate lateralty, each divides, One d aughter celi undergo ing repeated division torarin a capsule enclo sing the Other Which develops into the cord - like Ovary. The capsules extend mediaily, each as a duci, the two ducis j Oining and provid-ing a Single Ventral extension connecting to the genital bursa formed in the

Male genital primordia have not been detected, the testes heing known Only as appearing Suddenly in their adult position. Terat ological evidence indicates that the male reproductive SyStem develops froni genital primordia in XI, similar to the se male genital primordia. The stud y of a 4- annulate tand-leech possessing a duplication of the male median region, provided a basis for the analysis of previousty recorde d

'A study conducted under an award from the Australian Research Granis Committe esOr regearches On Australian aquatio und terrestriat leeches.

Acta Mologica Academiae Scientiarum Hungaricae 22, 1976