The arteries of the breasts come partly from the in tercostal, and partly from the superficial mammary arte ries ; and the nerves are derived, partly from the axil lacy plexus, and partly front the great sympathetics. The absorbents are numerous, and most of them pass to the axillary glands.
Before the age of puberty, the female breasts, like those of the male, are little inure than cutaneous tuber cles ; the nipples are flat, and the areola of a florid red colour. Ill children of both sexes, for some day s after birth, the breasts are much swelled, and very commonly contain a milky fluid ; but as this is gradually absorbed, they acquire the flatness just described. At the period of puberty, the breasts become plump, the nipples pro minent, and the areola less florid. But as old age ap proaches, and the fat, that always forms a principal part of their substance, is absorbed, these organs become small, flabby, and in those women who have borne many children, commonly pendulous.
The breasts are subject to most of the diseases that affect other secreting glands ; but the morbid appear ance most commonly observed in these organs is, that scirrhous hardness, or peculiar state of virulent ulcera tion which forms the distinguishing character of cancer.
See SURGERY.
Human milk differs from that of the cow, in being of a thinner consistence, and a bluish colour, though it con tains a greater quantity uf oily matter, and is of a much sweeter taste, The creamy part cannot be converted into butter by churning ; but il, after being agitated for some hours, it be sufkrcd to remain at rest for a clay or two, there is separated from it a thick, white, unctuous fluid, which floats on the surface of a watery liquor. Human milk is also not susceptible of coagulation by the usual methods employed to coagulate cow's milk, though it is certain that it contains curd as part of its composition. Hence it appears, that the milk of a wo man is distinguished from that of a cow, chiefly by three circumstances ; 1. Its oily part cannot be separated from the curd contained in the cream ; 2. Its serous part con tains much less curd ; and, 3. The whole fluid contains more sugar of milk.
Such of our readers as, from their professional avoca tions, require more particular information respecting the subjects of this chapter, may consult De Graaf 's Tractatus de Viroruni Organis Generationi, and de Mu lierum Organis Genfrationi Inservientihns ; Winslow's Traits: d'Anatonzie ; Albini Annotationt s Academicie, lib. iv.; Monro's Dissertatio Inauguralis de Testibus in -cards Animalibus, Edin. 1755.; Haller's kones Anatomicx, and
Opera Minora, torn. 1.; Hunter, On some parts (f the Animal I:conomy ; Bichat's Anatomic Descriptive, tom. v. ; (by Roux ;) Portal's Anatomie ilh.clicole, turn. V. Bell's Anatomy, vol. iv. ; Fyfe's Compendium qf Anatomy, vol. ii.; and ;Moreau's Histoire A'aturelle de la Femme.
In the view which we have now taken of the structure of the human body, we have adopted an arrangement which differs, in some respects, from that of ally anato mical work with which we are acquainted, though, in the general principles of our arrangement, and in the titles of our subdivisions, we have followed nearly the Lecons d'Anatomie Comparee of Cuvier, the Principes de Physi ologie of Dumas, and the Anatomic Descriptive of Xavier Bichat. We feel the necessity of explaining our mo tives for thus deviating from the beaten track of anato mical description, and conducting our readers into a new, though not untrodden path.
In the usual elementary treatises on anatomy, the subject is divided into seven parts, corresponding with the method according to which the earlier anatomists thonght proper to divide human body. Thus, as the body was said to be made up or (Pines, ligamnts, muscles, viscera, vessels, nerves, and glands, the science of anatomy was disided into Osmoi.ouv, treating of the bones and cartilages; S' NOKSNIOLOGN ol the ligaments; AlvoLonv, of the muscles ; Z,PLANe LINOLOGV,Oi the vis cera; ANGEIOLOttY, Of the vessels; NEUROLOGY, of the nerves; and ADENOLOO V, Of the glands. In tnis way, however, several parts of the body must have been either omitted, or described among those with which they have very little connexion. Anatomists preferred the lesser of the two evils; and accordingly we find the integu ments, and the organs of the senses, external as well as internal, described among the viscera. Again, by this division, parts which have an intimate connexion with each other, in office or situation, or both, are separated to a considerable distance. Thus, the heart is described in one division of the subject, the blood-vessels in another ; the gullet is separated from the stomacn ; the pancreas from the salivary glands; while the teeth are disjoined front the other masticating organs, and, along with the small bones of the ear, ttre described among the organs of support and motion inI t.se skeleton. Titus, the uses of the parts are overlooked in a servile attention to similarity of structure.