. Chimæroid fishes and their development. Fishes; Chimaeridae. 40 chim;eroid fishes and their development. terminating near the cardiac region. To add, therefore, a couple of inches to the length of the capsule involves a serious problem in the matter of space. This has been solved as follows : The capsule is gradually released, so that it comes to project from the fish's body ; at first the apex appears at the mouth of the oviduct, then the trunk-sheath, then the tail-sheath (fig. 12). If at this time the egg is dislodged, an abortive terminal results, as in plate 11, fig. 10. If it remains,
. Chimæroid fishes and their development. Fishes; Chimaeridae. 40 chim;eroid fishes and their development. terminating near the cardiac region. To add, therefore, a couple of inches to the length of the capsule involves a serious problem in the matter of space. This has been solved as follows : The capsule is gradually released, so that it comes to project from the fish's body ; at first the apex appears at the mouth of the oviduct, then the trunk-sheath, then the tail-sheath (fig. 12). If at this time the egg is dislodged, an abortive terminal results, as in plate 11, fig. 10. If it remains, the process in the formation of the capsular filament and terminal organ progresses as seen in plate i, fig. 4. The capsule now protrudes as far as the base of the filament, and with this. Figs. 24-26.—Egg-capsules of Chimaera colliei. partly opened, so as lo show egg and young. Natural size. 24. Lale blastula (about 9 days). 25. Early gastruia (about 19 days). 26. Late gastrula (about 24 days). protrusion occur many changes in the oviduct {cf. plate ii, fig 4, and plate 11, fig. 6), e. g., its diameter becomes greatly constricted and its dorsoventral characters and web creases obsolescent ; it also loses its earlier differentiation into trunk-sheath and tail-sheath forming portions, and its vaginal region is extended headward, the remaining part of the oviduct becoming corresponding!}- reduced. All these changes are to the obvious end of molding the long capsular filament and the bulbous terminal organ (plate i, fig. 4, c. f., and c. 0.). For the formation of the latter serves a special region of the capsular gland, /. r., its hindmost zone, a portion pinkish in color, provided with the recesses into which the terminal organ has been traced. * * Finally, a note may be given as to the probable mode o£ attachment of the capsule {cf. pp. 26, 27.) It is evident that the oviduct can be greatly evaginated at the time the egg is deposited (plate i, fig. 2I, and with this phenomen
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectfishes, bookyear1906
