  We present a spectral and timing analysis of INTEGRAL observations of two
high mass X-ray binaries, 4U 1538-522 and 4U 1907+09. Our timing measurements
for 4U 1538-522 find the pulse period to have exhibited a spin-up trend until
approximately 2009, after which there is evidence for a torque reversal, with
the source beginning to spin down to the most recently-measured period of
525.407 +/- 0.001 s. The most recent INTEGRAL observations of 4U 1907+09 are
not found to yield statistically significant pulse periods due to the
significantly lower flux from the source compared to 4U 1538-522. A spectral
model consisting of a power-law continuum with an exponential cutoff and
modified by two cyclotron resonance scattering features is found to fit both
sources well, with the cyclotron scattering features detected at ~22 and ~49
keV for 4U 1538-522 and at ~18 and ~36 keV in 4U 1907+09. The spectral
parameters of 4U 1538-522 are generally not found to vary significantly with
flux, and there is little to no variation across the torque reversal. Examining
our results in conjunction with previous work, we find no evidence for a
correlation between cyclotron line energy and luminosity for 4U 1538-522. 4U
1907+09 shows evidence for a positive correlation between cyclotron line energy
and luminosity, which would make it the fourth, and lowest-luminosity,
cyclotron line source to exhibit this relationship
