Published online by Cambridge University Press: 13 May 2016
I review the emerging picture of galaxy formation and evolution that is coming from observations in the optical waveband and in the submillimeter waveband. In the former I look at the work of several groups but in the latter I focus on the results from the Canada-UK Deep Submillimeter Survey (CUDSS), an 850 micron survey of about 100 square arcmin of sky carried out with SCUBA to a limiting flux of 3 mJy. I discuss what we do and do not know about the sources responsible for emitting a significant fraction of the extragalactic background at 850 microns.