**Figure 2.** **Reproductively old mice ovulate fewer eggs than reproductively young mice, but the proportion of normal and degenerate eggs does not differ between age groups.** (**A**) The number of eggs ovulated into the oviducts of each mouse was tracked, and the graph shows the average number of eggs ovulated per mouse (N = 11 mice per age group, 22 oviducts). A t-test was performed; asterisks denote P < 0.0001. Data are represented as mean **±** SEM. The number of morphologically normal eggs ovulated and retrieved from each oviduct from (**B**) reproductively young and (**C**) old individual mice. Representative brightfield microscopy images of morphologically (**D**) normal and (**E**) degenerate eggs. Scale bars are 100 μm. (**F**) The graph shows the proportion of morphologically normal and degenerate eggs ovulated from both age cohorts.