Haeckel's Evolution of Man. This plate represents the embryos of two of the lower, and two of the higher Vertebrates in three different stages: of a fish (F); of an amphibian (salamandar,S); of a reptile (tortoise,T); and of a bird (chick,A).

Licence: Public Domain Mark

Credit: Haeckel's Evolution of Man. This plate represents the embryos of two of the lower, and two of the higher Vertebrates in three different stages: of a fish (F); of an amphibian (salamandar,S); of a reptile (tortoise,T); and of a bird (chick,A). Wellcome Collection. Source: Wellcome Collection.