|
Monotremata 单孔目 单孔目 Monotremata n 1: coextensive with the subclass Prototheria [ synonym: { Monotremata}, { order Monotremata}] Mammalia \ Mam* ma" li* a\, n. pl. [ NL., from L. mammalis. See { Mammal}.] ( Zool.) The highest class of Vertebrata. The young are nourished for a time by milk, or an analogous fluid, secreted by the mammary glands of the mother. [ 1913 Webster] Note: Mammalia are divided into three subclasses; [ 1913 Webster] I. { Placentalia}. This subclass embraces all the higher orders, including man. In these the fetus is attached to the uterus by a placenta. [ 1913 Webster] II. { Marsupialia}. In these no placenta is formed, and the young, which are born at an early state of development, are carried for a time attached to the teats, and usually protected by a marsupial pouch. The opossum, kangaroo, wombat, and koala are examples. [ 1913 Webster] III. { Monotremata}. In this group, which includes the genera { Echidna} and { Ornithorhynchus}, the female lays large eggs resembling those of a bird or lizard, and the young, which are hatched like those of birds, are nourished by a watery secretion from the imperfectly developed mammae. [ 1913 Webster]
Monotremata \ Mon` o* trem" a* ta\, n. pl. [ NL., fr. Gr. mo` nos single ? hole.] ( Zool.) A subclass of Mammalia, having a cloaca in which the ducts of the urinary, genital, and alimentary systems terminate, as in birds. The female lays eggs like a bird. See { Duck mole}, under { Duck}, and { Echidna}. [ 1913 Webster]
|
安装中文字典英文字典查询工具!
中文字典英文字典工具:
英文字典中文字典相关资料:
|