The Ontogenesis can be explained in a double way:
historically: it runs from the past to the present.
idealistically: it runs from the general to the special.
The development of the dimorphism of sex tells against the historical and for the idealistical perception.
Therefore the idealistical morphology has to be put in the place of the phylogenetical.
Idiogenesis and Morphogenesis are going analogically from the general to the special. There exists parallelism of the order of thinking and being.