There must sometimes be a physical impossibility in the male element reaching the ovule, as would be the case with a plant having a pistil too long for the pollen-tubes to reach the ovarium.

有时雄性成分到达胚珠在理上是不， 例如雌蕊太长以至于花粉管无法到达子房植就是这情况。

In certain whole groups of plants the ovules stand erect, and in others they are suspended; and within the same ovarium of some few plants, one ovule holds the former and a second ovule the latter position.

在某些整植， 胚珠直立，而在另一些植， 胚珠则悬空；在少数植同一个子房内， 一个胚珠占据前者位置， 第二个胚珠占据后者位置。

If so, the position of the ovules, even when one is erect and the other suspended within the same ovarium, would follow the selection of any slight deviations in position which favoured their fertilisation, and the production of seed.

如果是这样， 胚珠位置， 即使一个直立而另一个悬置在同一个子房内，也将遵循有利于它们受精和子生产任何轻微位置偏差选择。