==============+========================================================= | Year or combination of years represented by each sample +-----------+-----------+-----------+----------+---------- | 1949 | 1950 | 1953 | 1956 | 1959 Years of Age | | 1951 | 1954 | 1957 | 1960 | | 1952 | 1955 | 1958 | 1961 | | | | | 1962 --------------+-----------+-----------+-----------+----------+---------- 1 | 54 | 44 | 39 | 39 | 41 2 | 14 | 24 | 21 | 19 | 19 3 | 18 | 11 | 23 | 16 | 13 4 | 4 | 10 | 10 | 11 | 9 5 | 6 | 6 | 3 | 8 | 8 6 | 2 | 1 | 3 | 1 | 3 7 | 2 | 4 | 4 | 2 | 3 8 | ...... | ...... | ...... | .5 | 2 9 | ...... | 1 | .4 | .5 | 2 10 | ...... | ...... | .4 | 2 | 1 Older than 10 | ...... | ...... | ...... | .5 | ..... | | | | | Number in | | | | | sample | 49 | 126 | 117 | 194 | 242 --------------+-----------+-----------+-----------+----------+---------- Although figures for the youngest age groups--one-year-olds and hatchlings--are missing, approximations of them may be furnished by extrapolation, from the information available regarding the productivity of the population. Some factors involved in productivity are that the sex ratio deviates from parity, slightly in favor of the females in the adolescents but more markedly in favor of the females among the older age groups; that some adult females apparently fail to produce eggs in the breeding season, but the percentage decreases in the older snakes; and that number of eggs per clutch increases in proportion to the size and age of the female producing them. Too few figures are available concerning most of these factors to indicate more than the trends; nevertheless the available figures have been used in Table 20 in an attempt to estimate the productivity of a hypothetical population. _Numbers_ Conant (1938:178, Pl. 7) published a photograph of 106 blue racers killed in February, 1932, by farmers near Bellville, Ohio, and Pope (1944:173) mentioned that scores of blue racers aggregated in October around an oak-covered dune near Chicago. In both these instances large hibernating aggregations were involved, and the areas represented by them are unknown; nothing has been recorded regarding population densities.