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Drosophila germ granules are structured and contain homotypic mRNA clusters.

One of the two halves of bilaterally symmetrical animals; one of any opposite symmetrical or homotypic parts in animals and plants.

In one of the reduction divisions all the chromosomes divide as in ordinary or homotypic nucleus division, but in the other the chromosomes simply separate into two equal groups without division.

If there are an odd number of chromosomes, 2_N_-1, in all the gametocytes of the male, as stated in most accounts of the subject, then if one chromosome fails to divide in the homotypic division, we shall have 2_N_-2 in one spermatocyte and 2_N_-1 in the other.

It is evident that what Dr. Wilson means is that the sex-chromosome is unpaired, and that although it divides like the others in the homotypic division, in the heterotypic division it has no mate and so passes with half the number of chromosomes to one pole of the division spindle, while the other group of chromosomes has no sex-chromosome.