Rat: E16-sag-339  1 = Lateral Ventricle  2 = Telecephalon  3 = Diencephalon  4 = III Ventricle (diocoel)  5 = Mesencephalon  6 = IV Ventricle  7 = Pons  8 = Tela choroïdea (initiation of cerebellum)  9 = Pharynx  10 = Thymus  11 = Trachea  12 = Pericardium  13 = Lung initiation  14 = Ductus venosus  15 = Liver  16 = Intestine  17 = Heart  18 = Tongue  19 = Oral cavity  20 = Nose epithelium  21 = Vertebrates Rager staining. Sagittal section acquired with a 2.5x objective

http://www.vcbio.science.ru.nl/en/virtuallessons/embryology/rat-E16-sag-339/print/