This report summarizes incidental information on fetuses recovered from pregnant mule deer (Odocoileus h. hemionus) on the National Bison Range, Moiese, Montana. Fetus-doe ratio.-The mean number of fetuses per pregnant doe, as I determined it in 1955-56, did not differ significantly from that determined for the same herd by Sears (1955) in 1953-54 (Table 1). The ratio of 1.66 is based on all age classes combined, although Sears (ibid.) found the highest reproduction rate in the National Bison Range herd to be in the 4to 5-year-old age classes, and the lowest rate in the 1to 2-year-old age classes. The over-all Utah data (Robinette and Gashwiler, 1950) yielded a ratio of 1.61 and the Interstate Deer Herd (Chattin, 1948) had a ratio of 1.75. The composition of any deer herd in respect to its age classes is a factor in determining the fetus per pregnant doe ratio.