The real source of _all_ the blood in the body of the child is a mystery; it would certainly appear most likely for the whole of it to be derived from the mother's vessels, but there are many circumstances which make it probable that the child may form some itself, by digesting the fluid it is supposed to absorb. This view is supported by the fact that there is found in its bowels at birth, and even before, a greenish substance like excrement, called _Meconium_. This has every appearance of being the product of digestion, though some suppose it to be derived from the liver. It occasionally contains hair, and other anomalous substances. CHAPTER IV. THE BREAST. The Breasts, or _Mammæ_, are not needed in the process of generation, nor are they absolutely necessary even after birth; but as they are naturally associated, in the majority of cases, with infantile nutrition, and are besides liable to many derangements and diseases during pregnancy and child-birth, it is advisable to give some account of them. When one of the breasts is dissected it is found to be composed chiefly of a singular body called the _Mammary Gland_, which resembles somewhat a very firm piece of fat, of a yellowish drab color. In the substance of this Gland are an immense number of little cells, or vessels, in which, by some unexplainable process, the milk is secreted, or made from the blood. From these little vessels there proceeds small tubes which gradually unite into larger ones, and these again into larger ones still, until at last all the milk is poured into a few tubes, or canals, which terminate in the nipple. The outer mouths of these terminal canals are only slightly contracted together, so that the suction of the child's mouth, or even the pressure of the milk, when the breast is full, will force them open and allow the fluid to flow out. The following plate represents the structure of the Breast, and explains, as far as it can be explained, the manner in which it performs its functions. PLATE XII.--_a._ _a. a._ The cut edges of the skin.--_b. b._ The flaps of the skin thrown back.--_c. c. c._ The fat which covers the breast.--_d. d._ The cells of the Mammary gland.--_e. e. e._ The Tubes or canals, which convey the milk from the Gland to the Nipple.--_f._ The Nipple, cut down the middle, to show the ends of the milk tubes terminating in it; these are usually about fifteen or eighteen in number.--_x._ Shows a bunch of the little cells, with the tubes proceeding from them, as they appear when injected. [Illustration: THE FEMALE BREAST. Plate XII.--_a._ This Plate represents the structure of the Breast, and explains the manner in which it performs its functions.]