This is the chamber-master proper, or "sweater" in the tailoring trade.

Or he may act as distributor, receive the material, and undertake to find workers who will execute it at their own homes, he undertaking the responsibility of collection.
Where the workers are scattered over a large city area, or over a number of villages, this work of distribution, and its responsibility, may be considerable.

Lastly, there may be the "sub-contractor" proper, who undertakes to do a portion of a work already contracted for, and either finds materials and tools, and pays workers to work for him, or sublets parts of his contract to workers who provide their own materials and tools.

The mining and building trades contain various examples of such sub-contracts.

Now in none of these cases is the middleman a mere parasite.