. Outlines of zoology. Zoology. 266 CRUSTACEA. mother keeps her tail bent till the eggs are glued to the small swimmerets. Before this, however, sexual union has occurred. The male seizes the female with his great claws, throws her on her back, and deposits the seminal fluid on the ventral surface of the abdomen. The fluid flows down the canal formed by his first abdominal appendages, and these seem to be kept clear by the movements of the next pair, which. Fig. S6.—Section through the egg oiAstacus after the com- pletion of segmentation. (After Reichrnbach.) St. Stalk of the egg ; ch, chorion
. Outlines of zoology. Zoology. 266 CRUSTACEA. mother keeps her tail bent till the eggs are glued to the small swimmerets. Before this, however, sexual union has occurred. The male seizes the female with his great claws, throws her on her back, and deposits the seminal fluid on the ventral surface of the abdomen. The fluid flows down the canal formed by his first abdominal appendages, and these seem to be kept clear by the movements of the next pair, which. Fig. S6.—Section through the egg oiAstacus after the com- pletion of segmentation. (After Reichrnbach.) St. Stalk of the egg ; ch, chorion envelope ; hi, peripheral blastoderm, within which .ire the yolk pyramid-^ (dark). are also modified. On the abdomen of the female the agglutinated spermatozoa doubtless remain until the eggs are laid, when fertilisation in the strict sense is achieved. The Develoliiient has lieen very fully \vorked out, .nnd is of interest in being direct, without the metamorphosis so common anions the. 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 Thomson, J. Arthur (John Arthur), 1861-1933; Newbigin, Marion I. (Marion Isabel), 1869-1934; Smith, Preserved, 1880-1941. fmo. New York, D. Appleton & Co.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
