. Cytology, with special reference to the metazoan nucleus. Cells. (Fig. 68). In this genus the type number is 35 for the male; the chromosomes are rod-shaped. In some individuals, however, the number is reduced to 34 or 33 (spermatogonia). The 34 type has 33 rod-shaped and one V chromosome, while the 33 type has 31 rods and two V';^. The former case is in- teresting as an example of homologous chromo- somes behaving dif- ferently, for since there is only one V instead of a pair of them, linkage must have taken place between one member of each of two pairs of homologous chromo- somes, the othe
. Cytology, with special reference to the metazoan nucleus. Cells. (Fig. 68). In this genus the type number is 35 for the male; the chromosomes are rod-shaped. In some individuals, however, the number is reduced to 34 or 33 (spermatogonia). The 34 type has 33 rod-shaped and one V chromosome, while the 33 type has 31 rods and two V';^. The former case is in- teresting as an example of homologous chromo- somes behaving dif- ferently, for since there is only one V instead of a pair of them, linkage must have taken place between one member of each of two pairs of homologous chromo- somes, the other mem- ber remaining free. That is to say, the chromosome formula is AB+A4-B+C-hC+ . . ' What happens in this case at syndesis ? While we do not know the details of this process, the result is clearly shown by the structure of the chromosomes of the first meiotic division. They consist, besides the sex chromosome, of fifteen ordinary biva- ^ "m-. 14 14 As 16 16. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Agar, Wilfred Eade, 1882-. London, Macmillan
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectcells, bookyear1920
