part_of part of part of develops from develops from ends during starts during ectoderm hatching gland frontal gland XAO:0000034 UBERON:0002538 A Y-shaped array of unicelluar glands on the top of the head, the open end of which faces anteriorly, that secrete an enzyme that dissolves or weakens the egg jelly and facilitates hatching. Presumptive cells of the hatching gland are present by the end of gastrualtion (NF stage 12.5) and differentiated cells start to form after neurulation is complete (NF stage 21). xenopus_anatomy embryonic structure hatching gland primordium NF stage 15 NF stage 35 and 36