The unsegmented egg in Peripatopsis breaks up into a 'first blastomere' and a number of nonnucleated 'cytoplasmic spheres', all of which float freely in a watery fluid (pp.
capensis, in both cases floating within very large membranes until the embryos grow to fill them (pp. The embryo then resembles the corresponding stage of P. balfouri the dilatation of the embryo is followed by a sudden contraction which causes the early elimination of the yolk sac. capensis this dilatation does not take place and no large yolk sac is formed, but the membrane dilates as in the former species. balfouri the absorption of the inner membrae is followed by another dilatation which expands the blastodermic vesicle to form the large yolk sac.
capensis the unsegmented egg swells and then remains constant in dimensions until the end of segmentation. The uterine eggs and embryos of Peripatopsis undergo two sudden increases in size. These membranes influence the shape and volume of the embryos, and their properties and functions are described (pp. In Peripatopsis an inner cuticular membrane is absorbed at the end of segmentation, and an outer chitinous membrane persists until birth. The first membrane is left behind in the ovary, two further membranes occur in the stages of Peripatopsis here described, and an outer 'shell' is present in oviparous species. There appear to be four different membranes round the eggs and embryos of the species of Onychophora at various stages of their development, and not two as previously supposed.
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