  I present results from a deep 12 micron extragalactic survey conducted with
the ISOCAM instrument. The survey covers about 0.1 sq. deg. in four fields and
reaches a 5 sigma flux limit of about 500 microJy. 50 sources are identified to
this flux limit. Of these, 37 are classified as galaxies on the basis of
optical/mid-IR colours using identifications from the USNO-A photographic
survey. Number counts for these objects exceed those predicted for no-evolution
models in simple models. However, these conclusions are somewhat dependent on
the assumed K-corrections. For this reason, and to better determine the nature
of the evolution of this population, followup observations are required to
determine redshifts, broadband optical-IR colours, and optical morphologies.
The first results from these followups are presented. Images and optical/IR
photometry for one of the four fields is discussed, and I also present the
first results from optical spectroscopy. The highest redshift for the sample so
far is z=1.2 for a broad-line object.

Astrophysics