. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. * t . .'W?^-. V/lvV?^ fi i,k\\ \N-. FIGS. 1-9. Chromosomes of Lcpas anatifera L. 1, 2, dividing intestinal cells. 3, spermatocyte in conjugation phase. 4-6, spermatocytes in first maturation division. 7, profile view of first meiotic spindle in the egg. 8, chromosomes in a first meiotic spindle which stands obliquely in the section. 9, polar view of the chromosome plate of the first meiotic spindle in the egg. All figures X 2000. advance of undisturbed chromosomal plates during anaphase. No un- even distribution of the chrom
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. * t . .'W?^-. V/lvV?^ fi i,k\\ \N-. FIGS. 1-9. Chromosomes of Lcpas anatifera L. 1, 2, dividing intestinal cells. 3, spermatocyte in conjugation phase. 4-6, spermatocytes in first maturation division. 7, profile view of first meiotic spindle in the egg. 8, chromosomes in a first meiotic spindle which stands obliquely in the section. 9, polar view of the chromosome plate of the first meiotic spindle in the egg. All figures X 2000. advance of undisturbed chromosomal plates during anaphase. No un- even distribution of the chromosomes is indicated and no chromatin elements are eliminated. The author was not able to count chromo- somes in the second meiotic division, though it was ascertained that no chromosome elimination occurred here, either. Lcpas, like many other crustaceans, brings periodically large num- bers of eggs to simultaneous maturity. In one specimen the ovary con- tained many thousands of eggs, all at the stage of metaphase of the first maturation division. The spindle which lies close to the surface of the oval egg has more than three times the linear dimensions of the cor- responding spermatocyte figure (compare Figs. 7 and 4). The chromo- somes are well separated since they are relatively smaller (barely twice the diameter of spermatocyte chromosomes; Figs. 9 and 6). The haploid number of 13 was established with greatest ease in more than two hundred individual counts. Three large chromosomes generally occupy the center of the plate while ten smaller ones usually take their. 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Red
Size: 1697px × 1473px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
