A manual of practical obstetrics . be seen radiating trabecular, be-tween which the pulp of the fruit is placed, that fairly resem-ble the radiating trabecular of fibrous tissue, fifteen or twentyin number, between which the so-called lobes of the secret-ing substance of the mammary gland are contained, andwhich are continuous with the circumferential fibrous capsuleof the organ. The lobes are made up of lobules, and thelobules of terminal culs-de-sac (acini) lined with columnarepithelium. Each acinus empties its secretion (the milkbeing formed by desquamation, fatty degeneration, and rup-ture
A manual of practical obstetrics . be seen radiating trabecular, be-tween which the pulp of the fruit is placed, that fairly resem-ble the radiating trabecular of fibrous tissue, fifteen or twentyin number, between which the so-called lobes of the secret-ing substance of the mammary gland are contained, andwhich are continuous with the circumferential fibrous capsuleof the organ. The lobes are made up of lobules, and thelobules of terminal culs-de-sac (acini) lined with columnarepithelium. Each acinus empties its secretion (the milkbeing formed by desquamation, fatty degeneration, and rup-ture of the epithelial cells) through a little duct, which uniteswith others to form a larger duct for the lobule, and thelobular ducts unite to terminate in a still larger duct for eachlobe, termed the galactophorous duct. The galactophorousducts, fifteen or twenty in number, one for each lobe, convergetoward the nipple, becoming widely dilated as they approachit, but,narrowing again as they actually enter it. (See Fig. 16.) Fig. 1^: V (Talactophorous ducts. Viewing the breast externally, we see the apex of themammary projection surmounted by a pink disk of skin calledthe areola. From the centre of the areola projects the nipple,and beneath the disk is a circular band of muscular fibres,which, in contracting, assists the expulsion of milk. As already stated, milk is formed by breaking down of thecell wall of the epithelium cells lining the acini of the mam-mary glands, and liberation of the cell contents, consisting offatty granules and liquid protoplasm. The free fatty granulescoalesce and aggregate together, and thus form larger massescalled milk-globules, which are still so small as to be micro- THE MAMMARY GLANDS. 67 scopic, and constitute a fatty emulsion with the more fluidportion of the milk in which they float. (See Fig. 15, page65.) During the first day or two of lactation, however, the par-ticles of fat are held together in masses of considerably largersize, having
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