. The Biological bulletin. Biology; Zoology; Marine biology. 68 V. D. MARZA, E. V. MARZA AND M. J. GUTHRIE Period 2 begins with the appearance of vesicles (proteinaceous yolk vesicles of Guthrie, 1928) in the oocytes and includes the remainder of the period of dififerentiation. During stage A^ of the second period there are few yolk vesicles and the diameter of the cell may be as great as 400 microns (Figs. 16, 17, and 18). The increase in number of yolk vesicles distinguishes stage A,, at the end of which only a narrow zone. Fig. 1. Diagram showing the stages in the growth-period of oocytes i
. The Biological bulletin. Biology; Zoology; Marine biology. 68 V. D. MARZA, E. V. MARZA AND M. J. GUTHRIE Period 2 begins with the appearance of vesicles (proteinaceous yolk vesicles of Guthrie, 1928) in the oocytes and includes the remainder of the period of dififerentiation. During stage A^ of the second period there are few yolk vesicles and the diameter of the cell may be as great as 400 microns (Figs. 16, 17, and 18). The increase in number of yolk vesicles distinguishes stage A,, at the end of which only a narrow zone. Fig. 1. Diagram showing the stages in the growth-period of oocytes in Fundulus which are referred to throughout the text. In the cytosome the circles which are empty represent the vesicles in which yolk may appear later; circles which are lined represent fat deposits; and circles which are solid represent either intra- or extravesicular yolk. of peripheral cytoplasm is free of vesicles and cells may be 600 microns in diameter (Fig. 14). Between the vesicles the internal cytoplasm is seen as a reticulum. The zona radiata appears at this stage, and the nucleus of the oocyte is increasingly eccentric. The beginning of stage Bi is marked by the initial appearance of globules of yolk (intra- vesicular yolk) within the vesicles (Figs. 10 and 13). During stage. 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 Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-; Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report; HighWire Press. Lancaster, Pa. [etc. ] : Lancaster Press, inc. [etc. ]
Size: 1655px × 1510px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectb, booksubjectzoology
