In its early embryonic condition it consists of three hollow vesicles, termed the hind-brain or rhombencephalon, the mid-brain or mesencephalon, and the fore-brain or prosencephalon; and the parts derived from each of these can be recognized in the adult (Fig. 677).    From Wordnik.com.  [IX. Neurology. 4. The Brain or Encephalon] Reference

The cephalic end of the neural groove exhibits several dilatations, which, when the tube is closed, assume the form of three vesicles; these constitute the three primary cerebral vesicles, and correspond respectively to the future fore-brain (prosencephalon), mid-brain (mesencephalon), and hind-brain (rhombencephalon) (Fig. 18).    From Wordnik.com.  [I. Embryology. 6. The Neural Groove and Tube] Reference