Areas of the central nervous system (brain and spinal cord) which consist mostly of myelinated axons (rather than cell bodies). The characteristic white color is due to the presence of myelin, which is mostly composed of lipids.
The part of the embryonic gonad that develops into the male reproductive ducts (epididymis, vas deferens, and seminal vesicles). In the female, this structure disappears because of the absence of anti-Müllerian hormone secreted by the Sertoli cells.
Posted: Saturday, March 30, 2013 Last updated: Thursday, November 19, 2015