Medusae of the world . studied from life by the author during the winter of 1907-08, atNaples, 2 had 12 tentacles, 4 had 13, 6 had 14, 4 had 15, 2 had 16, and 2 had 17 tentacles. This form bears some resemblance to Solmaris kucostyla, which also occurs in the Mediter-ranean but Maas, 1902, has shown that its development differs from that of Solmaris kuco-styla as described by Metschnikoff, 1886. S. flavescens of Vanhoffen, 1908, appears to be a Solmtssus. According to Maas, 1902, in S. flavescens the egg is fertilized in the water after beingdehisced from the ovary. It is opalescent, whitish,a
Medusae of the world . studied from life by the author during the winter of 1907-08, atNaples, 2 had 12 tentacles, 4 had 13, 6 had 14, 4 had 15, 2 had 16, and 2 had 17 tentacles. This form bears some resemblance to Solmaris kucostyla, which also occurs in the Mediter-ranean but Maas, 1902, has shown that its development differs from that of Solmaris kuco-styla as described by Metschnikoff, 1886. S. flavescens of Vanhoffen, 1908, appears to be a Solmtssus. According to Maas, 1902, in S. flavescens the egg is fertilized in the water after beingdehisced from the ovary. It is opalescent, whitish,and to mm. in diameter. The first twocleavages are meridional and give rise to 4 equal blastomeres. The third cleavage is equatorialand may result in 4 small and 4 large blastomeres, or in 8 equal blastomeres. When the cleav-age results in 4 small and 4 large blastomeres, the 4 small ones divide more rapidly than the 4large, giving a 12-cell stage; but where the 8 blastomeres are equal they divide again at one. Fig. 284.—Solmaris flavescens (Mgineta flavescens), afterGegenbaur, in Zeit. fur wissen. Zool., Bd. 8. —SOLMARIS. 435 and the same time, giving rise to a 16-cell stage. In any event, the cells of the upper (animal)pole usually divide so as to become smaller than those of the lower. No segmentation cavity isformed; but the superficial cells divide one after another and their inner-halves migrateinward to form a loose mass of cells which gives rise to the entoderm. The planula becomesoval in outline. The gallert forms a cap-like mass of gelatinous substance between the ecto-derm and entoderm at the upper end of the larva. The exumbrella entoderm cells are small
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcnidari, bookyear1910
