Definitions
from The Century Dictionary.
- noun That stage of the young of sponges (as Olynthus, Sycon, Haliphysema) in which, after ceasing to be a free-swimming embryo, and before it has changed into adult form by the development of spiculæ in the ectoderm, or other modifications, it becomes attached to some support. Haeckel.
- noun The first period of attachment of certain sponges, namely, that in which the sponge has lost or is losing its collar, opening the primitive cloacal collar, and forming the first central cavity without lateral ampullæ. It corresponds to the protospongian stage of Haeckel.
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Examples
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Physemaria (Prophysema), the simplest Sponges (Olynthus), the freshwater Polyps (Hydra), and the ascula-embryos of many other
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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Before these develop the hydra resembles an ascula (Figures 2.236 and 2.237).
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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