| OCR Text |
Show 580 MR. W. BATESON ON ABNORMAL [June 17, parts appear to be normal with the exception of the third maxilli-pede or the right side. This structure, however, has the form shown in fig. 1, A, differing entirely from the ordinary condition of the appendage. Fig. 1, B, is taken from the third maxillipede of the left side and shows the ordinary structure of the same parts. On comparing the two figures, it will be seen that the protopodite does not differ in the limbs of the two sides; that the exopodite of the right side is essentially like that of the left, but that it lacks the inner process and the flagellum which are borne by the normal part. There was some indication that this branch of the limb had been injured, and perhaps the flagellum may have been torn away, but the appearances were not such as to warrant a conclusion on this point. The branchial epipodites (not shown in the figures) were normal in both cases. The endopodite of the right side was entirely A represents the abnormal third maxillipede of the right side. B shows the same parts on the left side, which are normal. bp, protopodite : ep, epipodite ; dp, dactylopodite ; pp, propodite ; cp, carpo-podite ; mi, meropodite and ischiopodite ankylosed together, g indicates the line of their separation; g' corresponds to the groove at which a chela can be thrown off. peculiar and was, in fact, literally transmuted into the likeness one of the great chelae. It consists of a single joint (mi), articulating with the protopodite centrally and bearing the carpopodite. This single joint represents, as it were, the ischiopodite and meropodite of an ordinary chela, but these two parts are ankylosed together, and the articulation between them is only represented by a groove (g) ; another groove (g1) represents the groove upon the ischiopodite of the chela at which the limb is commonly thrown off by the animal if it is injured. The carpopodite, propodite, and dactylopodite are feebly movable on each other and hardly differ, save in absolute size, from those of the normal chela. The shape, proportions, and texture are all those of the chela. Cases like the foregoing, of the complete transformation of a part into the likeness of another part, though very common among |
