. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 338 M \KGARET K. PETERSON AND JOHN BUCK ( Kig. 2], it is seen that these cylinders arc arranged in triangular symmelix, each surrounded by a radial rosette t polyhedral photocytes. At the peripherv of the cylinders eacli twig terminates in a minute "(radical end organ" which pro- trudes into the body of a photoevte. Krom the end organs issue delicate tracheok's which can he followed but a short distance as they penetrate an external "differen- tiated zone" or cortex, staining differently from the interior
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 338 M \KGARET K. PETERSON AND JOHN BUCK ( Kig. 2], it is seen that these cylinders arc arranged in triangular symmelix, each surrounded by a radial rosette t polyhedral photocytes. At the peripherv of the cylinders eacli twig terminates in a minute "(radical end organ" which pro- trudes into the body of a photoevte. Krom the end organs issue delicate tracheok's which can he followed but a short distance as they penetrate an external "differen- tiated zone" or cortex, staining differently from the interior cytoplasm. In the Asiatic species the number of tracheoles originating from a single' tracheal twig is. FIGURE 3B. Low power electron micrograph of region of contact between a cylinder ami the photogenic layer, showing parts of three end organs ( Ed, EO-, EO::) and of three photo- cytes (pci, PCL', pc::). T', tracheal twig; t, tracheole in tracheolar cell; t', section of tracheole \\ithin photocyte cytoplasm enclosed by sheath of tracheolar cell cytoplasm and tracheolar cell membrane; n, nucleus of tracheal twig cell; NE, terminal portion of nerve; th, electron-dense thickenings along contact of end organ and photocyte membranes; m, photocyte mitochondria grouped around end organ; eg, clear-centered granules in cortical region of photocyte; pg, photocyte granule; cm, cell membrane of photocyte. Lucinhi sp. X 6600. apparently always two, in contrast to the three or four of PJiothins and the two or three (Smith, 1963) or three to seven ( Kluss, 1958) reported for Photnris. Previous electron microscopic studies of Phot in us ( Beams and Anderson, 1955) and Photnris (Kluss, 1958; Smith. 1CK>3) have shown that the tracheal "end cell" is actually a highly complex structure consisting of an inner tracheolar cell en-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of th
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
