. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 164 TI-CHOW TUNG, SU-HWEI KU AND YU-FUNG-YEH TUNG and the tail. The latter often turned dorsally, giving the larvae a curva- ture in an atypical direction. Figure 18 shows a larva of this kind. The neural cavity with two spots of sensory pigment is surrounded by the curved tail on one side. Conklin has suggested that the elongation of the neural plate and tube depends upon the normal elongation of the notochord. Our observations, however, do not lead to this conclusion. cA ms. ms So/i FIG. 17. Section of a larva from an egg
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 164 TI-CHOW TUNG, SU-HWEI KU AND YU-FUNG-YEH TUNG and the tail. The latter often turned dorsally, giving the larvae a curva- ture in an atypical direction. Figure 18 shows a larva of this kind. The neural cavity with two spots of sensory pigment is surrounded by the curved tail on one side. Conklin has suggested that the elongation of the neural plate and tube depends upon the normal elongation of the notochord. Our observations, however, do not lead to this conclusion. cA ms. ms So/i FIG. 17. Section of a larva from an egg centrifuged in capillary tube for forty minutes at 2193 times gravity, ch., notochord; ms., muscle cell; end., endoderm. FIG. 18. Sagittal section of a larva derived from an egg centrifuged one hour and thirty minutes at 2193 times gravity, showing the inverse body curvature. ch., notochord; ns., neural tissue; pg., pigment spot; ins., muscle cell. FIG. 19. a. Section of a larva from an egg centrifuged in a capillary tube for fifty minutes at 2585 times gravity. The left yolk-filled cells are endoderm and the right mitochondria-filled cells are ectoderm. b. Section of a larva from an egg centrifuged for fifteen minutes at 2193 times gravity. The yolk-filled cells form a superficial epithelium, ch., notochord; ect., ectoderm; end., endoderm; ms., muscle cell. The sense organs are also structures of interest. In typical larvae there are two sense organs, the eye and the otocyst, with their pigments situated on the wall of the brain vesicle. Typical organs are rarely formed in abnormal larvae; instead, pigment spots are found in un- expected places. The number of spots varies from none to four. Their. 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 Biolo
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
