Sentence:  It may be said that the sex question is both brain stem and pelvic stem in its fourfold <WSD>octavation</WSD> with its stabilizing governor, the pituitary body. These consist in coördination and correlation, the sex relation of <WSD>octavation</WSD> of voice and pitch. 
Meaning of the word marked with <WSD> tags:  Normalization of a numerical ratio by repeated multiplication or division by 2.