mammal

See mama. mamma2 (mam'ä), n. [L. mamma (> It. mamma = Sp. Pg. mama, L. dim. mamilla, > F. mamelle = AS. mam me) = Gr. μάμμη, the breast, pap. See тата.] 1. Pl. таттæ (-ē). The mammary gland and a ociated structures; the characteristic organ of the cla Mammal i a, which in the female secretes milk for the nourishment of the young; a breast or udder. The mamma is e entially a conglomerate gland, consisting of lobes and lobules, secreting milk, which is conveyed from the ultimate ramifications of the organ by a system of converging lactiferous or galactophorous ducts, to be discharged through one or several main orifices at the summit of the gland, where is the nipple or mammilla. The mamma is subcutaneous, and may be regarded as a highly developed and specialized sebaceous follicle. Mammæ vary much in number and position: they may be 2, 4, 6, 8, to 12 or more, usually an even mamma number, being paired, and may be pectoral, axillary, ventral or abdominal, or inguinal. They are sometimes quite high on the sides of the animal, but are never dorsal. An apparently single and median mamma, as the udder of the cow, results from the coalescence of as many mammæ as there are teats. In marsupials they are contained in the pouch, and may be circularly or irregularly disposed, or of odd number. In monotremes they are devoid of a nipple, whence the name Amasta for these ani mals. The mamma develops at puberty, and comes into functional activity during gestation. The structure is common to both sexes, but as a rule remains rudimentary and functionle in the male. 2. [ cap.] A genus of sea-snails of the family Naticida. Klein, 1753. mammal (mam'al), a. and n. = [= OF. mam It = mal = Sp. mamal Pg. mamal, mammal mammale, n.; the breast: see mamma2.] I. a. Having breasts or teats; mammiferous. II. n. An animal of the cla Mammal i a . Aërial mammals, the bats. - Age of mammals, the Tertiary period in geology. Mammal i a (ma-mali a), n. pl. [NL. (sc. ani mali a ), neut. pl. of LL. mammal is (neut. sing. as a noun, mammale ), of the breast: see mammal. ] In zoöl., the highest cla of Vertebrata, containing all those animals which suckle their young, and no others; mammiferous animals; the mammals. With the exception of the lowest subcla , the monotremes or Ornithodelphia, which lay eggs like birds, Mammal i a are viviparous, bringing forth their young alive; and, with the same exception, the mammary gland is provided with a nipple for the young to suck. They have no gills, but breathe air by means of lungs, which are primitively an offset of the alimentary canal. The is warm; is IMG:content-0150.png:[blocks in formation]