The part of the embryonic mesoderm, consisting of loosely packed, unspecialized cells set in a gelatinous ground substance, from which connective tissue, bone, cartilage, and the circulatory and lymphatic systems develop.

• 间叶细胞胚胎的中胚层部分，由生长于胶状基质的、结构松散的、无特定功能的细胞组成，这些细胞将会发育成结缔组织、骨、软骨、血液及淋巴系统