1921/05/01 by Franz Schräder · 4 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Chromosomal and Genetic Variations #Animal Genetics and Reproduction
paper · doi:10.2307/1536736
openalex publication_date 1921/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2025/11/06
1. The diploid number of chromosomes in Pseudococcus nipæ is ten in both sexes. 2. In the maturation of the egg, five tetrads are formed and reduction is probably normal. 3. In the spermatogenesis, five chromosomes are developed before the others, and these tend to remain grouped together. 4. No tetrads are formed, and in reduction five chromosomes go to one pole (supposedly those evolved first) and five to the other. 5. Explanation of this seemingly anomalous behavior is to be sought in the fact that five of the chromosomes carry sex chromatin. 6. The case is not so much to be regarded as an illustration of Weismann's ideal type of reduction, as an exceptional example of reduction due to unusual sex chromatin distribution.