Figure 2

FSH and estrogen values from Figure1, reported by Stricker et al. [[5]], shown as a phase plane graph. Data points are labeled with days of the cycle. They form a pattern that resembles the leaning “&" symbol. Other published data produced very similar phase plane graphs [4, 6–9], so it can be assumed that any set of ovulatory cycle data would provide similar patterns. This pattern is described in the The follicular phase to Lutheolysis.