Ornithodorus turicata Duges is a common vector of relapsing fever in Texas. It appears to have a fairly wide distribution over the state but is more common to the south central part where it is found in sandy caves. The life history does not appear to differ very much from that of other members of the same genus. Once infected the tick remains so for life. All stages are infective and infection may be produced merely by the act of biting. As indicated by Wolbach's studies on Br. duttoni and Br. kochi in O. moubata, ingested spirochetes make their way very quickly to practically every organ of the body. The large numbers found in connective tissue seem to indicate multiplication without, possibly, any definite cycle of development. Infection may be hereditary in this tick. O. turicata and the relapsing fever spirochete of Texas appear to be rather closely adapted one to the other.