. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. Development of the Embryo in the Egg of Toxoptera graminum. Fig. 1.—Longitudinal section showing the blastoderm partly formed, being farthest advanced in the anterior region. The mass of ovarian yolk is lodged at the posterior pole. Figures la and lb represent the yolk cells magnified !S45 diameters. Fig. 2.—Longitudinal section showing the thickening of the blastoderm about the ovarian yolk previous to invagination. Magnified 156 diameters. Fig. 3.—Longitudinal section representing the germ band at the beginning
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. Development of the Embryo in the Egg of Toxoptera graminum. Fig. 1.—Longitudinal section showing the blastoderm partly formed, being farthest advanced in the anterior region. The mass of ovarian yolk is lodged at the posterior pole. Figures la and lb represent the yolk cells magnified !S45 diameters. Fig. 2.—Longitudinal section showing the thickening of the blastoderm about the ovarian yolk previous to invagination. Magnified 156 diameters. Fig. 3.—Longitudinal section representing the germ band at the beginning of invagination, folding inward about the ovarian yolk. Magnified 156 diameters. Fig. 3a.—Section of the blastoderm. Magnified 430 diameters. Fig. 4.—Longitudinal section of a more advanced stage of invagination, the germ baud having almost closed over the ovarian yolk. Magnified 15a diameters. (Original.). 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 Entomology. Washington : G. P. O.
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Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectentomology
