Page:Popular Science Monthly Volume 5.djvu/204

192 were of the same individual—it was simply the childhood, youth, and manhood, of one person. Many years ago the naturalist described a little crustacean which was noticed swimming gayly and briskly in the sea. It was a pert little thing, rather pretty, and very quaint. It had large, full eyes. In fact, they were enormously so for such a diminutive being. Between these great optics, projecting downward like the coulter of a plough, was a long, sharp spine. On each side of the body was a much shorter spine, and over this short spine on each side, and high up near the back, were two fan-like structures, almost suggestive of wings, as with these four it really sped its way through the water. Between these, and from its back, rose by far the longest spine, almost equal to its entire self in length. It was immensely long, yet delicate and sharp. This outré little thing received the name Zoëa pelagica. In rank it was considered an entomostracan, the lowest, the very pariah of the race. The naturalists also found another little crustacean, something larger, and not so testy-looking either. It had not the formidable spines, but it had feet on the abdomen, which Zoe had not. There were also other great differences. It had, however, like Zoe, large eyes; and so the systematists named it Megalops. Well, just here the joke comes in, if indeed we may suppose a joke possible in so serious a science as zoology, especially in the department of the crabs. But the fact was that Zoe, and Megalops, and Cancer, were but the childhood, youth, and adult stages of the same individual, namely, the crab. Now, as Cancer by common consent belongs rightly to the highest crustacean rank—that is, the decapods—so do Zoëa and Megalops.

The common edible crab of Europe has for its scientific name



Cancer pagurus. It is a much more massive crab than our edible crabs; individuals have been known to weigh twelve pounds each! Let the reader compare the cut of the European crab. Fig. 1, with that