The external mechanics of the chromosomes, VII. Abnormal mitosis in the pollen-grain

1. All unbalanced samples of pollen from polyploid species ofTulipa, Fritillaria, Hyacinthus, andTradescantia have variable spiralisation at metaphase of their first mitosis, owing to the direct action of the individual genotype. 2. This variation reaches an extreme in two tetraploid species ofTulipa where the chromosomes are excessively contracted in… CONTINUE READING