Polyembryony is of common occurrence among the gymnosperms. This is possible because more than one archegonia are fertilized and more than one zygotes are formed. These develops into embryos, but only one of them succeeds in developing into a complete embryo. In the conifers there is a cleavage polyembryony. In this case all the four cells of the young embryo separate and develop into 4 embryos, but only one completely develop and others abort, eg Pinus.