pēi céng
germ layer
layer of tissue in embryology
wài pēi céng
ectoderm (cell lineage in embryology)
zhōng pēi céng
mesoderm (cell lineage in embryology)
nèi pēi céng
endoderm (cell lineage in embryology)
sān pēi céng dòng wù
triploblastic animals (having three germ layers)