Wax injection model of the mammary duct tree

On the Anatomy of the Breast, Plate V, Fig. 1. Cooper's caption reads "Lactiferous tubes, injected with red wax, in a woman who died during the period of lactation. Twelve ducts have been filled and ligatures are placed on their orifices. The ducts are seen forming large reservoirs at the roots of the mamillary tubes; these reservoirs are seen to be produced by the union of numerous branches from the ducts. The ducts are perceived to terminate at the margin of the gland in branches, but in some parts, in glandules." Glandular tissue is most obvious at 3 to 5 o'clock and 10 to 11 o'clock. This may be the first published suggestion of significant biological variation between human mammary gland lobes.