. Bulletin of the Bureau of Fisheries. Fisheries; Fish culture. BAI-RDIELLA CHRYSUR.\ AND ANCHOVIA MITCHILLI. 7 posterior, i. e., the embryonic pole of the blastoderm. At this pole a broad tongue of cells, several layers in depth, may be observed before any evidence of invagination is apparent around the rest of the periphery of the blastoderm. Figure 7, plate 11, illus- trates an early stage in the differentiation of the germ ring. In this blastoderm invagi- nation was not yet apparent. The following figure (fig. 8) illustrates a blastoderm in which the broad tongue of cells is already growin
. Bulletin of the Bureau of Fisheries. Fisheries; Fish culture. BAI-RDIELLA CHRYSUR.\ AND ANCHOVIA MITCHILLI. 7 posterior, i. e., the embryonic pole of the blastoderm. At this pole a broad tongue of cells, several layers in depth, may be observed before any evidence of invagination is apparent around the rest of the periphery of the blastoderm. Figure 7, plate 11, illus- trates an early stage in the differentiation of the germ ring. In this blastoderm invagi- nation was not yet apparent. The following figure (fig. 8) illustrates a blastoderm in which the broad tongue of cells is already growing forward from the embryonic pole, and the entire germ ring is well differentiated. At this stage the central area of the blastoderm has become materially thinner than the peripheral area. Viewed from the under side the blastoderm is now distinctly concave. Between its concave surface and the periblast there is a perceptible subgerminal cavity closed in on all sides by the germ ring. The blastoderm gradually increases in size by centrifugal growth. The germ ring, therefore, which in its earlier stages is comparatively narrow, increases in width both by the invagination of the marginal cells and by the centrifugal growth of the â ^. 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 United States. Bureau of Fisheries. Washington, D. C. : Govt. Print. Off.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectfisheries, bookyear19
