. Electron microscopy; proceedings of the Stockholm Conference, September, 1956. Electron microscopy. Fig. 3. Fibrillar zone of a contracted melanophore, the width being about microns. Magnification 20,000. Fig. 4. Fibrillar zone of a dispersed melanophore, the width being about micron. Magnification 17,000. Fig. 5. Longitudinally cut fibrils. Magnification x 33,000. Fig. 6. Transversely cut fibrils. Magnification < 55,000. membranes. The width of this fibrillar zone varies with the pigment dispersion. By fully dispersed melanophores the width is about n and by fully concentrate
. Electron microscopy; proceedings of the Stockholm Conference, September, 1956. Electron microscopy. Fig. 3. Fibrillar zone of a contracted melanophore, the width being about microns. Magnification 20,000. Fig. 4. Fibrillar zone of a dispersed melanophore, the width being about micron. Magnification 17,000. Fig. 5. Longitudinally cut fibrils. Magnification x 33,000. Fig. 6. Transversely cut fibrils. Magnification < 55,000. membranes. The width of this fibrillar zone varies with the pigment dispersion. By fully dispersed melanophores the width is about n and by fully concentrated melanophores the width is about 3 n (figs. 3-6). The fibrils are regarded as representing contrac- tile structures, which as a basket mesh-work surround the inner sack. Thus when the fibrils contract, the. Fig. 7. Schematic representation of the observations made on teleost melanophores. sack diminishes and the pigment granules are con- centrated. On the other hand when the fibrils relax, the sack can increase and the granules will be dis- persed. The suggestion is thus made that the migration of the pigment granules within the teleost melano- phores should be due to the contracting and relaxing fibrils in the zone between the two cell membranes. From a physiological point of view it also seems to be the concentration of the pigment granules that requires most energy. This investigation gives a completely new explana- tion of the mechanism of pigment migration within teleost melanophores. It abolishes many previous theories of pigment migration (1. 3-9). This work has been supported by a grant from the Kungliga Fysiografiska Sallskapet, Lund. References 1. Ballowitz, E., Pfltigers Arch. ges. Physiol. 157, 165 (1914). 2. Du Buy, H. G., Woods, M. Bdrk, D., and Lackey, M. D., /. Nat. Cancer Inst. 9. 325 (1949). 3. Franz, \., 30, 194(1939). 4. Hooker, D., Amer. J. Anai. 16, 237 (1914). 5. KoLTZOFF, N. K., Compi. rend. acad. sci. URSS, 28, 554 (1940). 6. Mars
Size: 1668px × 1498px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, bookleafnumber231
