Plate VIII. represents the individual development of the first and non-sexual generation of Star-fishes, that is, of the _nurses_ (usually, but erroneously, called larvæ). These nurses possess the form-value of a simple, unsegmented worm-individual. Fig. 1 represents the egg of the four Star-fishes; and it, in all essential points, agrees with that of man and of other animals. (Compare vol. i. p. 297, Fig. 5.) As in man, the protoplasm of the egg-cell (the yolk) is surrounded by a thick, structureless membrane (zona pellucida), and contains a globular, cell-kernel (nucleus), as clear as glass, which again encloses a nucleolus. Out of the fertilised egg of the Star-fish (Fig. _A_ 1) there develops in the first place, by the repeated sub-division of cells, a globular mass of homogeneous cells (Fig. 6, vol. i. p. 299), and this changes into a very simple nurse, which has almost the same shape as a wooden shoe (Fig. _A_ 2-_D_ 2). The edge of the opening of the shoe is bordered by a fringe of cilia, the ciliary movements of which keep the microscopically small and transparent nurse swimming about freely in the sea. This fringe of cilia is marked in Fig. _A_ 2-_A_ 4, on Plate VII., by the narrow alternately light and dark seam. The nurse then, in the first place, forms a perfectly simple intestinal canal for nutrition, mouth (_o_), stomach (_m_) and anus (_a_). Later, the windings of the fringe of cilia become more complicated, and there arise arm-like processes (Fig. _A_ 3-_D_ 3). In sea-stars (_A_ 4) and sea-urchins (_C_ 4) these arm-like processes, which are fringed with cilia, afterwards become very long. But in the case of sea-lilies (_B_ 3) and sea-cucumbers (_D_ 4), instead of this, the fringe of cilia, which at first, through winding in and out, forms one closed ring, changes subsequently into a succession of separate ciliated girdles, one lying behind the other.