We report the results of a submillimeter dust continuum survey of the protoclusters NGC 2068 and NGC 2071 in Orion B carried out at 850 \ > \mu m and 450 \ > \mu m with SCUBA on JCMT .
The mapped region is \sim 32 \arcmin \times 18 \arcmin in size ( \sim 4 pc \times 2 pc ) and consists of filamentary dense cores which break up into small-scale ( \sim 5 000 AU ) fragments , including 70 starless condensations and 5 circumstellar envelopes/disks .
The starless condensations , seen on the same spatial scales as protostellar envelopes , are likely to be gravitationally bound and pre-stellar in nature .
Their mass spectrum , ranging from \sim 0.3 ~ { } M _ { \odot } to \sim 5 ~ { } M _ { \odot } , is reminiscent of the stellar initial mass function ( IMF ) .
Their mass-size relation suggests that they originate from gravitationally-driven fragmentation .
We thus argue that pre-collapse cloud fragmentation plays a major role in shaping the IMF .