It is composed of comparatively small perforated plates through which
pass the suckers or locomotive appendages. On either side of the
furrows are other plates corresponding to the plates of the broad zones
in the Sea-Urchin. Where shall we look for the five eyes? Of course, at
the tip of every ray; exactly where they were when the rays were drawn
up to form the summit of a sphere, so that the eyes, which are now at
their extremities, were clustered together at their point of meeting.
Where shall we look for the ovarian plates? At each angle of the five
rays, because, when the broad zones of which they formed the summit
were divided, they followed the split, and now occupy the place which,
though it seems so different on the surface of the Star-Fish, is
nevertheless, relatively to the rest of the body, the same as they
occupied in the Sea-Urchin. Assuming, as we premised, that the central
area of the ab-oral region, forming the space between the plates at the
summit of the zones in the Sea-Urchin, is elastic, it has stretched
with the spreading out of the zones, following the indentation between
the rays, and now forms the whole upper surface of the body. All the
internal organs of the animal lie between the oral and ab-oral
regions, just as they did in the Sea-Urchin, only that in the Star-
Fish these regions are coequal in extent, while in the Sea-Urchin the
ab-oral region is very contracted, and the oral region with the parts
belonging to it occupies the greater part of its surface.
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