Nature's microscopic art forms

Radiolarians and diatoms drawn by Ernst Haeckel.

Computer-enhanced examples of Haeckel's painstaking work. Credit: SCOTT CAMAZINE/SPL

Design in nature, a source of inspiration both to the artist and the engineer, has also solicited the attention of philosophers in the past. Where do the stunning beauty and elegance of the microscopic exoskeletons of radiolaria and diatoms come from? These works of natural micro-architecture were revealed for the first time to an astonished scientific community in the late nineteenth century, when the British research vessel HMS Challenger collected sediments from the seabed. The wonders of Challenger's booty were painstakingly drawn and catalogued by the German biologist Ernst Haeckel.

Haeckel's legacy to art, science and design is explored in the More Than Meets the Eye exhibition currently at the Victoria and Albert Museum in London (see Nature 407, 20; 2000). The exhibition features a display that looks at biomimetic elements of art and engineering, ranging from art nouveau to the geodesic domes of US architect Richard Buckminster Fuller and the 'soap-film', and tent-like structures of German architect Frei Otto.

Buckminster Fuller's domes are echoed in the spherical exoskeleton of the radiolarian Aulonia hexagona, one of those lovingly drawn by Haeckel for his portfolio Art Forms in Nature, published between 1899 and 1904. Haeckel's illustration shows the occasional pentagons in the web of hexagonal cells, and necessary (as eighteenth-century Swiss mathematician Leonhard Euler showed) to produce curvature and close the sphere.

These radiolaria were not the first microscopic 'art forms' to be identified in nature. Christian Ehrenberg observed delicately patterned coccolithophore shells in chalk in 1836 — but concluded that they were inorganic formations. By that time, studies by biologists, including Thomas Huxley, had convinced most others that coccoliths were biogenic.

Yet the range and inventiveness of designs in radiolarians and diatoms were quite unprecedented. Such discoveries inspired a strong interest in natural form in the early twentieth century, most famously expressed in D'Arcy Wentworth Thompson's On Growth and Form (1917). Yet while the Scottish naturalist was busy showing in meticulous detail that these 'watches' needed no maker beyond the laws of physics and mechanics, his compatriot James Bell Pettigrew at the University of St Andrews was at work constructing a kind of theistic argument from design in his Designs in Nature (1908). Pettigrew saw the imprint of continual intervention from the divine in the geometric forms of nature.

Both men had to come to terms with what Haeckel himself had said on the matter. In Haeckel, science, art and philosophy combined to produce a heady brew, and strongly flavoured by the German Naturphilosophie instigated by Johann Wolfgang von Goethe (whom Haeckel idolized). Haeckel is perhaps best regarded as a mystical atheist, sharing a Nietzschean belief that “Man creates God in his own image” and yet prepared to embrace the idea of a life-giving spirit that permeated matter even down to the atomic level.

This outlook is encapsulated in Haeckel's book Crystal Souls (1917) in which he presciently attempts to link the geometry of radiolaria with the discovery of liquid crystals by Friedrich Reinitzer in 1888. Otto Lehmann, the German physicist who helped the botanist Reinitzer make sense of his discovery, suggestedin 1904 that liquid crystals were intermediate between living , non-living matter. We now know that liquid crystals can indeed organize themselves spontaneously into ordered aggregates that provide templates for the formation of inorganic materials regularly patterned on the microscopic scale, and that this mimics some of the processes of biomineralization that occur in radiolaria.

Haeckel's contributions came at a time when Darwin's evolutionary theory was provoking debate both about the origin of life and about political theory: Marx and Engels were grappling with its implications. Blended with the nationalism that was in the air in Germany and with Haeckel's political ambitions, this lends some of and Haeckel's views — such as those on eugenics — the taint of racial élitism from which Naturphilosophie has never been entirely free.

Yet his gorgeous illustrations had a wide impact, reaching the eyes of the art nouveau artists and their counterparts, the Jungenstil group, in Germany. Nature's ornamentation blossomed throughout Europe.