of a sample of nearby galaxies (see also @sakon04 [@onaka07]). As stated by @hibi06, this implies that the optical properties of grains in FIR are common among the Milky Way and nearby galaxies.

Since the FIR colour–colour relation can be used to constrain the optical properties of dust grains, the FIR colour–colour relation of galaxies with various evolutionary stages provides pieces of information on the grain evolution in galactic environments. In particular, the dominant production source of dust grain could be different in early phase of galaxy evolution [@todini01; @nozawa03; @maiolino04; @schneider04]. Moreover, the effects of interstellar processing of dust grains, especially accretion of heavy elements onto dust grains, coagulation, and shattering, depend on metallicity (or dust abundance). Thus, it is probable that the grain properties evolve as galaxies evolve.

Although it is difficult to obtain the rest-frame FIR data of distant galaxies in an early phase of galaxy evolution, there are nearby possible “templates” of primeval galaxies, blue compact dwarf galaxies (BCDs). Indeed, BCDs have on-going star formation in metal-poor and gas-rich environments [@sargent70; @vanzee98], which could be similar to those in high-redshift star-forming galaxies. Moreover, BCDs harbour an appreciable amount of dust [e.g. @thuan99] and can be used 