nipple sheath formation
The developmental process pertaining to the initial formation of the nipple sheath from the unspecified epidermis. This process begins with a circular ingrowth of the epidermis around the region of the mammary sprout. It ends before the region begins to elevate.
GO:0048646
anatomical structure formation involved in morphogenesis
is_a
GO:0060658
nipple morphogenesis
part_of