title: [Abnormal development of some embryos of lineus ruber (O. F. Müller) (Heteronemertine)].
abstract: One can observe in the case ofLineus ruber, two types of development in the same egg string, a normal one and an abortive one. The eggs which give the normal embryos, give two polar bodies while the eggs which give the abnormal embryos, issue one polar body only, they are not fertilized but start to divide and belatedly reach the stade of 16-32 blastomeres.The existence of an abortive parthehogenesis is suggested and the mechanism of abnormal development is discussed.
authors.affiliation: Laboratoire de Biologie cellulaire et Centre de Biologie du Développement, Reims, France.
authors.forename: Marie Josèphe
authors.initials: MJ
authors.lastname: Alluchon-Gerard
authors.affiliation: Laboratoire de Biologie cellulaire et Centre de Biologie du Développement, Reims, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Gontcharoff