part of develops from ends during starts during endoderm archenteron The cavity of the gastrula forming a primitive gut. At NF stage 20-21 its wide canal becomes dorso-ventrally compressed and narrowed in the future trunk region so that a subdivision into a foregut, a midgut and a hindgut with protruding endodermal mass becomes manifest. UBERON:0004735 xenopus_anatomy gastrocoel XAO:0000092 anatomical space NF stage 10 NF stage 37 and 38