Table 3.

Mean proportional allocation to spermatogenic tissue in seven populations of Utterbackia imbecillis, listed in order of increasing selfing rate

Population	N	Proportional male allocation
		Mean	(95% CI)
Oklawaha River	4	0.61	0.59–0.64
Dead River Lake	6	0.60	0.40–0.77
Little River	5	0.19	0.09–0.28
Mill Creek	6	0.24	0.16–0.32
Suntree Pond	6	0.40	0.34–0.49
Pickering Creek	6	0.35	0.19–0.51
Suwannee River Canal	4	0.30	0.24–0.36

For each individual, total spermatogenic and oogenic areas were determined by summing over four equidistant cross-sections through the visceral mass. Confidence intervals (CI) were determined as ordered observations 250 and 9,750 from 10,000 bootstrap random samples (with replacement) of N individuals for each population. N, number of individuals.