Spermatogenesis in gecko japonicus (dumeril and bibron)

The nuclear changes involved in the two maturation divisions of G. japonicus have been studied in considerable detail. All observations compel a telosynaptic interpretation. The duality, an apparent parasynapsis, as seen beginning from synizesis up to diplotene is a result of a longitudinal splitting of the chromosomes joined end to end. Strepsinema is brought about by breaking up of the diplotene thread into segments, which really are pairs of synaptic mates in end‐to‐end union; each segment then bends at its middle to form V‐ or ring‐tetrads. There are altogether twenty tetrads. All chromosomes assume a rod shape when in the metaphase plate. A pair of heterochromosomes was observed to be slower than the rest in assuming the rod shape and in getting into the plate. The marching of the synaptic mates toward their respective poles is asynchronous. Second division begins right after the chromosomes have reached the poles. Zwischenkörper observed at the end of the second division are regarded as formed by the granules seen in the polar regions during the first division.