. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 284 BASH FORD DEAN. elasmobranchs, that it is taken up by the embryo. It is probable that it is appropriated via gills (which may become trophone- mata, as shown by Wood-Mason, Alcock, Haswell and others), and gut. This stage is of further interest from the stand- point of the morphology of the chimojroid head, for it demon- strates that the autostylous character of the skull is secondary, as had indeed been surmised from the time of Johannes Miiller. As indicated in Fig. 19, from a drawing of a wax-plate model,. FIG. 19. Sk
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 284 BASH FORD DEAN. elasmobranchs, that it is taken up by the embryo. It is probable that it is appropriated via gills (which may become trophone- mata, as shown by Wood-Mason, Alcock, Haswell and others), and gut. This stage is of further interest from the stand- point of the morphology of the chimojroid head, for it demon- strates that the autostylous character of the skull is secondary, as had indeed been surmised from the time of Johannes Miiller. As indicated in Fig. 19, from a drawing of a wax-plate model,. FIG. 19. Skull of embryo shown in Fig. 6. After wax-plate model, palato-quadrate is shown fusing with the cranium at the points A and B. The the skull in this stage shows the upper jaw (palate-quadrate) still separate, although even at this early stage its fusion with neighboring cranial cartilage is taking place at both its anterior, and posterior borders, A, B. Conspicuous in all early stages is the disproportionate size of the anterior and posterior body regions; head and anterior trunk are large, posterior trunk and tail dwindle away narrowly, the latter, however, attaining ex- treme length. These characters, together with the great size of the eyes in embryonic stages, are clearly in the line of preparing the young fish for the conditions of deep-water living. Conclusions.—The mode of development of CJdinccra affords evidence, I conclude, in support of the following theses. I. That sharks and chimaeroids are closely related geneti-. 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 original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods
Size: 1658px × 1508px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
