Neural tube ( NT ; Baer, 1837 ) : The embryonic primordium of the adult cerebrospinal axis (Meckel, 1817) that is formed from the neural plate (Stricker, 1860) by the process of neurulation; see Nieuwenhuys et al. (2008, pp. 7-9). Galen probably glimpsed the macrodissected mammalian neural tube (see Adelmann, 1966, p. 747) and Baer (1837, p. 59) introduced the term for macrodissected vertebrate embryos. Varolio (1573, see English translation, 1969, p. 34) observed three transparent globules (tres globulos transparentes in Latin) in the 9-day macrodissected chick embryo and Baer (1837, pp. 106, 107) called them the three primary brain vesicles (primären Hirnbläschen in German and Vesiculae cerebrales in Latin): anterior or forebrain primary vesicle (vordere Bläschen in German), middle or midbrain primary vesicle (mittleres Bläschen in German), and posterior or hindbrain primary vesicle (hinteres Bläschen in German). He also observed that they develop into 5 vesicles going on to form the 5 morphological elements or basic parts of the adult vertebrate brain (Cuvier, 1800): Vorderhirn, Zwischenhirn, Mittelhirn, Hinterhirn, and Nachhirn in the original German. Sharpey et al. (1867, p. 577) gave the English and Latin equivalents of these 5 parts: secondary forebrain or prosencephalon, interbrain or diencephalon, midbrain or mesencephalon, secondary hindbrain or epencephalon, and afterbrain or metencephalon. In the Foundational Model of Connectivity these 5 parts are called endbrain (Kuhlenbeck, 1927) or telencephalon (Kuhlenbeck, 1927), interbrain (Baer, 1837) or diencephalon (Sharpey et al., 1867), midbrain (Baer, 1837) or mesencephalon (Sharpey et al., 1867), hindbrain (Baer, 1837) or epencephalon (Sharpey et al., 1867), and afterbrain (Sharpey et al., 1967), metencephalon (Sharpey et al., 1867) or medulla (Winslow, 1733). The hindbrain (Baer, 1837) consists of cerebellum (Aristotle) and pons (Haller, 1747).