In the U.S.A., Australia, Switzerland, Wei Germany, and the U.S.S.R., the power of the Centre are enumerated in the constitution ; the residue is left to the units. The enumeration itself is not of a uniform type ; in the U.S.A., there is one list of exclusively federal subjects allotted to the Centre, with some prohibitions both on the Centre and on the units ; in Australia, Switzerland, and Weimar Germany, the Centre has power to pass laws on an exclusively federal list as well as on a concurrent list, Central laws in respect of concurrent subjects prevailing over those of the units ; in the U.S.S.R. there is only an exclusively federal list. The device of concurrent powers is specially noteworthy as it provides a plan by which the Centre can step in some matters when the Government of a unit is lazy or unprogressive and when the need for uniformity demands its interference, while leaving the initiative in the first instance to the units.