  We present observations of Halpha emission line profiles taken at Magellan
Observatory for a sample of 39 young low-mass stars and brown dwarfs in the
Taurus and Chamaeleon I star forming regions. We have identified 11 new
substellar accretors, more than tripling the number of known brown dwarfs with
measurable accretion activity. These include the lowest-mass objects yet seen
with accretion, with masses down to ~0.015 Msun. Using models of Halpha
emission produced in magnetospheric accretion flows, the most widely applicable
primary calibrator now available, we determine the first estimates of mass
accretion rates for objects at such extremely low masses. For the six objects
with masses < 0.03 Msun, we find accretion rates of ~ 5x10^{-12} Msun/yr, among
the smallest yet measured. These new results continue the trend of decreasing
mass accretion rate with decreasing (sub)stellar mass that we have noted
previously for samples of more massive objects; the overall correlation is Mdot
\~ M^{2.1}, and now extends over a mass range of over two orders of magnitude.
Finally, the absence of a discontinuity in the distribution of accretion rates
with mass tends to suggest that stars and brown dwarfs share similar formation
histories.
