Through the struggle of parts for room or for food an unused398 organ in the individual may be crowded (ontogenetic—Roux).
This species exhibits the progressive (ontogenetic as well as phylogenetic) development of Panartus amphiconus.
Superimposed on this geographic variation are ontogenetic changes, which are most noticeable in males.
Presence of the glands, therefore, cannot be correlated either with sexual or ontogenetic development.
In the same way we are in entire ignorance as to the physical mechanism of ontogenetic development, the evolution of the embryo.
The list below indicates the ontogenetic origin of the avian leg muscles, according to the studies of Romer and Wortham.
Parallelism between the ontogenetic and the phyletic vital force, 687.
Skulls of two series to be compared were matched in pairs so that they corresponded in size and ontogenetic stage of development.
The idea of ontogenetic degeneration is intimately bound up with the idea of phylogenetic degeneration.
Science may yet have to give up what the Germans call the "ontogenetic directive Force."
ontogenetic on·to·ge·net·ic (ŏn'tō-jə-nět'ĭk)
Of or relating to ontogeny.
ontogeny on·tog·e·ny (ŏn-tŏj'ə-nē)
The origin and development of an individual organism from embryo to adult. Also called ontogenesis.