Textbook of normal histology: including an account of the development of the tissues and of the organs . ise decided alterations in position and location of the granules of the dark-brown pigment are usually regarded ascomposed of melanin derived from the coloring-matters of the blood;recent investigations, however, render it probable that, while appar-ently the same, the dark pigment found within the various tissues is byno means always identical in composition. The isolated particles whenexamined with high amplification are but slightly colored, the charac-teristic tint appearing o
Textbook of normal histology: including an account of the development of the tissues and of the organs . ise decided alterations in position and location of the granules of the dark-brown pigment are usually regarded ascomposed of melanin derived from the coloring-matters of the blood;recent investigations, however, render it probable that, while appar-ently the same, the dark pigment found within the various tissues is byno means always identical in composition. The isolated particles whenexamined with high amplification are but slightly colored, the charac-teristic tint appearing only when the pigment-granules are the colored particles are taken up by the cells as pre-existingpigment-granules, or whether they are produced within the proto-plasm of the cell, is still undecided ; the evidence, however, seems tofavor the conclusion that the particles possess an extra-cellular arrangement of the connective-tissue cells varies withthe age and density of the tissue. Wherethe cells retain thestellate type, a pro-toplasmic net-workextending through- Fig. Plate-like connective-tissue cells found in tendon. Cell-spaces of dense con-nective tissue in which thecells lie: silvered ground-substance ; from the cornea. Connective - tissue (corneal) corpus-cles : these cells occupy the spaceswithin the ground-substance. out the tissue is formed by the union of the processes; examples ofsuch disposition are seen in young mucoid tissues, the cornea, andother connective substances rich in cells. Parallel rows of closely- THE CONNECTIVE TISSUES. 39 placed quadrate elements are seen in tendon, while sheets of flattenedendothelioid plates characterize basement-membranes and envelopthe bundles of fibrous tissue. In the denser structures the cells occupy spaces within theground-substance ; these spaces usually communicate directly withone another by means of minute channels, or canaliculi, and form acomplicated system of juice-canals through the en
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