. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 484 JOHN BELLING. has arms which taper to the center, the two homologues having apparently joined at the constrictions. The last two drawings in the lowest line of Fig. 3 are the same bivalent at two different focusses, apparently showing one transverse and one reflexed. FIG. 3. Camera drawings of eight bivalents. ' The four crosses have the nodes at different points, but always at equal distances from the ends of the homologues. The lowest arm of the second cross in the second line is much foreshortened. The last two figure
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 484 JOHN BELLING. has arms which taper to the center, the two homologues having apparently joined at the constrictions. The last two drawings in the lowest line of Fig. 3 are the same bivalent at two different focusses, apparently showing one transverse and one reflexed. FIG. 3. Camera drawings of eight bivalents. ' The four crosses have the nodes at different points, but always at equal distances from the ends of the homologues. The lowest arm of the second cross in the second line is much foreshortened. The last two figures show the effects of change of focus on the node. chromatid of one homologue, the same thing being often ob- servable at a different focus in the other homologue also. These are pulled out by the spindle fibers which are attached at the apex of the bend at the median constriction. One hundred and sixteen of the long bivalents were classified in six groups (Diagram i), mostly after squeezing chromosomes and cytoplasm from the cell. The results were (Diagram i): 38 cases of the ring and V; 20 X's; and 4 figures of 8 (totalling 62 with one node); 37 cases of the double ring and V; 10 cases of the ring and two V's; and 7 cases of a triple ring; totalling 54 cases with two nodes. No bivalents with triple nodes were certainly demonstrated. If only two chromatids underwent segmental interchange at any one node, as seems to be indicated. 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-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
