Adjective
Haeckelian (comparative more Haeckelian, superlative most Haeckelian)
Of or relating to the zoologist Ernst Haeckel (1834-1919).
Although Stephen Jay Gould's 1977 book Ontogeny and Phylogeny helps to reassess Haeckelian embryology, it does not address the controversy over Haeckel's embryo drawings. Source: Internet
These elements of his thinking about development have thus survived, whereas his theory of recapitulation has not. citation Modern status The Haeckelian form of recapitulation theory is considered defunct. Source: Internet