Of the 89 cottontails observed in the study, 35 were captured in live-traps only once and were never seen in the field or trailed. The remaining 54 served for calculation of home range by one or more methods. The minimum, maximum and average home ranges for these 54 individuals were calculated by each of five methods. All individuals for which any area was recorded were included in the average. Incomplete home ranges lower the averages. According to the most reliable method (Composite Method) 30 male cottontails had home ranges of between 0.46 acre and 12.19 acres and 24 female cottontails had home ranges of between 0.46 acre and 12.62 acres. The average for males was 5.05 acres and the average for females was 4.81 acres. The average for all 54 cottontails was 4.86 acres. Because of irregularities in live-trapping and field observation some cottontails were more intensively studied than were others; one cottontail was followed one time only, while another was trapped 26 times, followed three times, and seen in the field six times. It was necessary to determine which cottontails had been studied sufficiently to determine the approximate extent of their home ranges. [Illustration: FIG. 1. Correlation between average size of home range and number of "peripheral points" (marginal records, which form angles when the range is outlined). On the average, a sufficient number of records to yield approximately nine peripheral points must be obtained before the full extent of the home range is revealed.] The average area, in acres, of home range was plotted, on a graph, against the number of peripheral points (Figure 1). When a home range had nine or more peripheral points, on an average, the size of home range did not increase significantly with additional captures, observations in the field, or records of trails. Home ranges with less than nine peripheral points were likely to be increased in size with each new observation. A similar situation has been shown by previous authors who have plotted the size of home range against number of captures in live-traps, where only live-trapping was used to gather data. Therefore, in my study, home ranges with nine or more peripheral points were considered to be adequately studied.