Quarterly journal of microscopical science . ey are bestseen in transverse (optical) section, fig. 2, which shoAvs thedigestive cavity h, with its walls, still composed of largecells, separated by the remains of the original cleavage cavityc (now the general cavity of the body) from the body wallcomposed of smaller cells, and raised. At w the body wall israised up into the above-mentioned folds which thus giverise to the groove /. New cells may also be seen to havemade their appearance between the outer and inner sacsbeneath the folds. Although Kowalevsky was unable to trace out step by stepth
Quarterly journal of microscopical science . ey are bestseen in transverse (optical) section, fig. 2, which shoAvs thedigestive cavity h, with its walls, still composed of largecells, separated by the remains of the original cleavage cavityc (now the general cavity of the body) from the body wallcomposed of smaller cells, and raised. At w the body wall israised up into the above-mentioned folds which thus giverise to the groove /. New cells may also be seen to havemade their appearance between the outer and inner sacsbeneath the folds. Although Kowalevsky was unable to trace out step by stepthe arching over and coalescence of the (medullary) folds, hebelieves that they do thus behave ; at all events an hour laterwe meet with the form shown in fig. 3, in which h is, asbefore the alimentary cavity, surrounded by its wall of cellsg, and c is the general cavity of the body. Outside the body isnow a new cavity, n, as yet opening externally at its front bythe orifice d, and roofed in by a double layer of cells originat-
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherlondo, bookyear1870
