. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 206 H. P. KJERSCHOW-AGERSBORG. 4), or along a line drawn between vorderer Interradius-hinterer Radius (Fig. i). Delage and Herouard claim that the relation of the madreporite is far from being precise, and their orientation of the asteroid plan corresponds to Ritter and Crocker's figures of young individuals, if they be inverted. This is true, however, only in a general sense for the madreporite which comes on the right side, but the anus is placed in the same relative position in either case. This relation is different in t
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 206 H. P. KJERSCHOW-AGERSBORG. 4), or along a line drawn between vorderer Interradius-hinterer Radius (Fig. i). Delage and Herouard claim that the relation of the madreporite is far from being precise, and their orientation of the asteroid plan corresponds to Ritter and Crocker's figures of young individuals, if they be inverted. This is true, however, only in a general sense for the madreporite which comes on the right side, but the anus is placed in the same relative position in either case. This relation is different in the adult. Here the madreporite is on the left ante- rior side between the rays I. and V. and actually corresponds to Ludwig's plan. But the so-called five primary rays of Ritter and Crocker, which, according to Ludwig ('99), correspond to 3-IV.,. FIG. 4. Young individual, aboral view, in the eight-rayed stage (from Rit- ter and Crocker) ; the sketch is inverted to show the probably anterior rays (I-V) and their relation to the madreporite and the anus, nip, a, respectively. A, the posterior primary ray. (Compare this figure with Figs. 6, 7, 8, 9). The labeling is retained as in the original. 2-III., i-II., 5-!., 4-V., respectively (Fig. 6), for the larva and the ground-plan of the common starfish, are not the posterior rays in adult life of Pycnopodia, however, but the anterior rays. This is easily seen in an actively moving individual, and may also be readily learned from the study of the interpolation zones which lie between rays 11. -VI., It seems quite reasonable that the movements of Pycnopodia should be in the direction of, or along the axis of, the oldest rays, with the oldest rays as determiners of direction of movements. For, as I have shown before ('18), this. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the
Size: 1551px × 1611px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
