the mechanism of the pigment granule motion is undetermined although there are studies concerning pe ultrastructure ( 8 , 23 , 31 ) , scanning electron microscopy of the fingerlike extensions of the pe cells ( 27 ) , the role of the pe in photoreceptor phagocytosis ( 32 ) , the nature of the pigment granules ( 19 ) , and the action spectrum of the light which induces the migration ( 16 ) .
C0007634
cells
C0031308
phagocytosis