He started with mouse embryos and graduated to goats, whose large mammary glands make better milk machines.

FORBES: Charlotte's Goat

Researchers are "growing" the spider's silk inside Mille and Muscade's mammary glands.

FORBES: Charlotte's Goat

Even cave women have the same, two simple mammary glands.

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By injecting the orb weaver gene into the father of Mille and Muscade, Nexia bred she-goats with mammary glands able to produce the complex proteins that make up spider silk.

FORBES: Charlotte's Goat