ABSTRACT
Ecological embryology is just beginning to develop, and that sets certain limits in the choice of subjects for study. Such subjects must be ecologically distinct, amenable to accurate and detailed ecological analysis, and perfectly studied morphologically. Embryology and carpology, depending on the tasks set, can be perfectly emcompassed by research at the organism level. The theoretical significance of the direction developed — evolutionary ecological embryology—is that the ecological-morphological approach permits objectively to determine the trends of evolutionary modifications in ontogenesis, revealing the complexes of mesological and etological factors that stipulated such modifications. Interaction of ecological factors can be followed on the example of adaptive evolution of certain ecologically distinct groups of flowering plants. Transition of a number of flowering plants to root parasitism was induced essentially by insufficient humidity of soil. Various types of sexual processes are observed in plants: for example, isogamous, heterogamous, and oogamous. Oogamy alone is inherent in the flowering plants.
