STUDIES OF SPERMATOGENESIS IN THE HEPATICAE

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Abstract
Spermatids of the liverwort Marchantia polymorpha were shown by analysis of thin-sections to contain a 4-layered organelle, the Vlerergruppe, lying between the flagellar bases above and a subjacent mitochondrial body. The uppermost layer consists of parallel tubules structurally similar to those of the axoneme. Some of the tubules extend beyond the 4-layered region to form a long ribbon-like appendage. The 2nd layer consists of low, vertical, membranous fins connected by numerous short links to the tubules above. The 3rd layer, limited above and below by 2 horizontal membranes, consists of vertical partitions, apparently continuous with the fins. The 4th and lowermost layer consists of narrow parallel tubules aligned beneath alternate partitions. The long axes of the lower 3 layers are parallel to each other and He at an angle of 48[degree] to the tubule axis of the uppermost stratum. A graphic representation of 3-dimensional scale model interpreting organelle structure is given. The Vierergruppe supersedes Drelergruppe interpretation in most if not all of the bryophytes studies to date.