Magnetic susceptibility, paramagnetic resonance, and antiferromagnetic resonance have been measured in MnTi0 3 , FeTi0 3 , CoTi0 3 , and NiTi0 3 . N6el temperatures T N of 65, 56, 37, and 23±2°K, respectively, have been measured. The molar susceptibilities appear to obey a Curie-Weiss law with C m =4.36, 3.37, 3.72, and 1.24°K, and with paramagnetic Curie temperatures 9 P =-219, +32, -9.3, and -11°K, respectively. The effective spectroscopic splitting factors consistent with this law and with paramagnetic resonance are gef f =2.01, 2.13,2.83,2.22±0.01. The susceptibility of MnTi0 3 exhibits a broad peak near 100°K rather than a well-defined peak at TV. No antiferromagnetic resonance was observed in FeTi0 3 , and no paramagnetic resonance was observed in FeTi0 3 or CoTi0 3 . The antiferromagnetic resonant frequencies, extrapolated to 0°K, are 156,145, and 187 kMc/sec for MnTi0 3 , CoTi0 3 , and NiTi0 3 , respectively. A low-frequency mode of 19.1 kMc/sec was also detected in NiTi0 3 . In the system Mni-^Mg^TiOs, both a R and T N decrease roughly linearly with x in the range 0<#<0.075.