Wharton's jelly
Wharton's jelly (substantia gelatinea funiculi umbilicalis) is a gelatinous substance within the umbilical cord also present in vitreous humor of the eyeball, largely made up of mucopolysaccharides (hyaluronic acid and chondroitin sulfate). It also contains some fibroblasts and macrophages. It is derived from extra-embryonic mesoderm.