. The microscope and its revelations. o be the peculiar seat of thecolour of the skin ; it received the desig-nation of Malpighian layer or rete iniwosn 776.—Cells from the pig- The change in form is accompanied by ammtnin nit/mm of the eye: change in the chemical composition of the e noticed in the epidermis of the negro and other dark races, andare most distinguishable in the Malpighian layer, their colour ap-pearing to lade as they pass towards the Mirfaee. The most remark-able development of pigment-cells in the higher animals, however,is on the inner surface of the ehoroid coat, of
. The microscope and its revelations. o be the peculiar seat of thecolour of the skin ; it received the desig-nation of Malpighian layer or rete iniwosn 776.—Cells from the pig- The change in form is accompanied by ammtnin nit/mm of the eye: change in the chemical composition of the e noticed in the epidermis of the negro and other dark races, andare most distinguishable in the Malpighian layer, their colour ap-pearing to lade as they pass towards the Mirfaee. The most remark-able development of pigment-cells in the higher animals, however,is on the inner surface of the ehoroid coat, of the eye, where theyha\e a very regular arrangement, and form several layers, known as. EPIDERMIS 1043 the pujinentum uti/runi. When examined separately these cells arefound to have a polygonal form (fig. 776, ft), and to have a distinctnucleus (b) in their interior. The black colour is due to the accu-mulation, within each cell, of a number of flat rounded or ovalgranules, of extreme minuteness, which exhibit an active movementwhen set free from the cell, and even whilst inclosed within pigment-cells are not always, however, of this simply rounded orpolygonal form ; they sometimes present remarkable stellate pro-longations, under which form they are well seen in the skin of thefrog (fig. 791,cc). The gradual formation of these prolongationsmay be traced in the pigment-cells of the tadpole during its meta-morphosis (fig. 777). Similar varieties ofform are to be met with in the pigmentarycells of fishes and small Crustacea, whichalso present a great variety of hues; andthese seem to take the colour of the bottomover which the animal may live, so as toserve the bett
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
