It has been said that the members of the Senate divideinto two groups: those who look into the bathroom mirror each morning imagining they hear "Hail to the Chief, " and those who do not -- with the latter list thought to be the shorter.
Modern mammals divideinto three overarching groups: the placentals (most species, including man), the marsupials (kangaroos and their like) and the monotremes (the egg-laying platypus and echidnas).