Ernst Haeckel: Phylogeny as
Mechanical Cause of Ontogeny
Es ist ein ewiges Leben, Warden und Bewegen in ihr. Sie verwandelt sich ewig,
und ist kein Moment Stillstehen in ihr. Fur's Bleiben hat sie keinen Begriff, und
ihren Fluch hat sie an's Stillstehen gehangt. Sie ist fest: ihr Tritt ist gemessen,
ihre Gesetze unwandelbar.
Goethe on Nature, quoted by Haeckel
on title page of Generelle Morphologic, 1866
The law of recapitulation was "discovered" many times in the decade following 1859. Fritz Mtiller applied it in his masterful Für Darwin
(1864), a short treatise on Darwinian explanations for crustacean
morphology. He did not grant to recapitulation the universal status
afforded it by his successors. Cope and Hyatt, the intellectual
descendants of Agassiz in America, published their first works on
recapitulation independently in 1866. In that same year, Haeckel's
Generelle Morphologie der Organismen made its appearance; Huxley
called it "one of the greatest scientific works ever published" (quoted
in McCabe's footnotes to Haeckel, 1905).
Ernst Haeckel, son of a government lawyer, was born in Potsdam in
1834. He took a medical degree in 1858 and, after a short practice,
moved to Jena to study zoology under the great anatomist Carl
Gegenbaur. He became professor of zoology and comparative anatomy in Jena in 1862 and remained there until his death in 1919.
Haeckel published major treatises on three protist and invertebrate
groups: Radiolaria (Die Radiolarien, 1862-1868), calcareous sponges
(Die Kalkschwdmme, 1872), and medusae (Das System der Medusen, 1879).
But his dominating influence grew from two articles on the "gastraea
theory" (1874 and 1875, though the idea was first promulgated in
1872, p. 467), and especially from three books: Generelle Morphologie
(lSQ6),NatürlicheSchöpfungsgeschichte (1868), andAnthropogenie (1874).
Haeckel conceived the books as popular works, but they contain a
great amount of complex detail amidst speculation both bold and
absurd. All deal heavily in phyletic reconstruction. His famous evolutionary trees first appear as plates in the second volume of Generelle Morphologie; Haeckel's trees have their roots (and most of their
branches) in the principle of recapitulation—the "biogenetic law."*
"Ontogeny is the short and rapid recapitulation of phylogeny . . .
Haeckel was an inveterate coiner of terms; many words, common to scientists and
laymen alike, were his invention: ecology, ontogeny, phylogeny. But most died with
him, among them "biogeny"—the genesis of the history of organic evolution. Thus his
phrase "biogenetic law" is often misunderstood, or at least not granted the force that
Haeckel intended; for, under his definition, it is the law of the history of evolution.