part of morphogenesis of embryonic epithelium mammary gland cord formation biological_process GO:0060616 2009-05-18T08:57:58Z The process in which the mammary gland cord forms by elongation of the mammary bud. The cord is formed once the elongating bud breaks through the mesenchyme and reaches the fat pad. mammary gland sprout formation dph mammary gland cord morphogenesis epithelial tube formation