Embryonic and Fetal Development:

• Mammary gland originate from ectoderm.
• Appearance of mammary band just back to the umbilicus.
• Mammary Band divides into two narrow band called mammary line.
• Further proliferation leads to the formation of mammary buds.
• Down growth of mammary band to mesenchyme results in formation of primary sprout.
• Canalization of primary sprout from lumen.
• Then secondary and later divides into tertiary sprout.
• Formation of udder takes place.
• Primary and secondary sprout present at birth and tertiary sprout appears later.