Sentence:  Third, to this hundred per cent. structural equipment of our remote ancestors phylogeny adds a hitherto unperceived germinal potentiality of specialization along certain pre-determined directions rather than others in adaptive reactions to changes of environment; this <WSD>teleogenesis</WSD> rests upon thousands of observations among primates, horses, titanotheres and elephants which prove that parallel anatomical and psychical progress is traceable to germinal community of origin. 
Meaning of the word marked with <WSD> tags:  The preferential evolution of features and organs in certain ways