granular layer of cerebellar cortex cerebellum external granule cell layer MA:0000994 granule cell layer Transient layer of the cerebellar cortex present during development which is composed of dividing and migrating granule cells[MP]. BIRNLEX:797 The granule neurons migrate from the exterior layer to form an inner layer known as the internal granule layer. The external granular layer ceases to exist in the mature cerebellum, leaving only granule cells in the internal granule layer[WP] granule layer UBERON:0008829 external granule layer outer granular layer of cerebellar cortex Wikipedia:Anatomy_of_the_cerebellum#Development UMLS:C1289480 UMLS:C0228473 EMAPA:35216 The transient layer of the cerebellar cortex present during development which is composed of the dividing and migrating granule cell[MGI:tc]