"The marking of the cow in Schönthal in Switzerland or the current state of crime registration of cows at pasture based on the cow herd of farmer Jenni": with this work Gerhard Lang introduces an element of humour in what is a serious fact of nature - animals and humans carry, on their skin, signs of their genetic make-up.

Moreover, by comparing regular and irregular markings (zebra or tigers, and cows or dogs), Lang raises the question of random patterning and its visual function. As an artist, he asks questions of visibility and identification on the basis of the viewer's mental and optical perceptions and taxonomies. The pre-dispositions of the observer of natural phenomena is in question as much as the phenomenon itself. Science is described by scientists, who are themselves biologically and culturally determined human beings. Hence Gerhard Lang refers to our categorisation of cow marking as a "visual concept', and questions, with suspicion, the apparently "arbitrary" pattern.

 Nature's design differs from the artist's drawn image. "The drawing worked out in our head shows the outcome of our thoughts, but does not necessarily reflect the cow's nature."

The artist's investigation, once again, comprises an on-site inspection of the natural phenomenon, within parameters borrowed from the sciences, in this particular case, criminology. (After all, DNA testing is also used in this area). Like Mendel, Lang's fascination with methods of systematic recording is intimately associated with an obsessive engagement with meteorological phenomena, such as cloud formation.

  The visual documentation of the cow's coat patterns is carried out with the most objective of graphic mechanical tools, the photograph. In 1994 Lang took a number of photographs of left- and right-side markings on cows and produced "composite photographs" of the "Typical Cow Marking on the Left" and the "Typical Cow Marking on the Right" in Schönthal in Switzerland.

The method of composite photography had been developed by the systematic classifier of human and natural data, including hereditary traits, and Charles Darwin's cousin, Francis Galton (1822-1911), who, unexpectedly, has a connection with Gregor Mendel. At the beginning of the 20th century (in some unpublished notes as part of his studies on heredity- now at the Old Manuscript Library at UCL) - Galton showed himself to be well aware of Mendel's work, and attempted to define Mendelism. In a series of letters to Charles Darwin (1875-76) Galton asked Darwin to grow peas on his behalf in order to validate the experiments he was carrying out in Mendel's footsteps. The letters centre around Darwin's studies of pangenesis of which Galton was very critical. It was Galton who recommended to Darwin that he should read W.O.Focke, who had written on heredity, and who cited Mendel.

 The focus of the artist's interest lies in codes, systems and patterns, which, she believes, represent underlying connections between apparently unrelated things. In the search for universal laws, codes and equations, she works by arranging, and colour-coding her material until she can observe naturally emerging patterns. In bird flight she observed that the co-ordinates of cranes flying in formation can be reduced to formulae on an x-y axis, and that a number of enlightening comparisons can be made between formations in different species.

 Her photographs of a herd of Friesian cows are taken with the intention of isolating and studying the markings on the backs of the animals. The artist's eye was struck by the similarity between the coat and markings of Friesian cows, and graphic representations of geographical maps and atlases. Her final work exploits her visual intuition by combining these patterns.

 Scientists are generally concerned with observing and describing what is not commonly and readily available or recognisable to the naked eye. In order to do this, they use special tools and methods. Artists who access similar tools and methods enter new territories which benefit from careful framing.

Cornelia Hesse-Honnegger, who trained as an illustrator at the University of Zürich in the department of zoology, began her work with scientific publications on taxonomy. She became increasingly interested in the fruit fly, Drosophila, and started breeding the insect in her own house, where she could observe it and draw it, recording its varieties and mutations.

 Visually attuned by her scrupulous earlier depictions of the patterned beauty of insect morphology, she exploits her perceptual and representational skills to draw our eyes into the miniature world of variant shapes. Some of the unusual configurations appeared to be genetic modifications caused by exposure to radiation. Hesse-Honnegger's work raises the sort of ethical issues which are so difficult to deal with in the context of science and human endeavour in general.

Her careful and accomplished watercolours, stand for her quest as artist, both to collaborate with scientists and to question the nature of scientific understanding in the contexts of the technical and social formation of knowledge.

The history of Natural History revolves around acts of naming and classification. This has most obviously been the case from the Linnaean and Darwinian eras, through to Mendel's, in which the concept of the species assumed such centrality. Naming and taxonomy are tools, functionally apposite according to the demands of the users, and capable of creative reshaping of our understanding.

 herman de vries, the Dutch artist, philosopher and poet, is a collector of natural things - things of a kind. But his 'kinds' stand in a complex and often challenging relationship to standard taxonomic categories, such as those in the herbaria and arboreta in which he has worked.

de vries has a collection of more than 2,400 samples of earth, including no less than 300 from Gröningen in Holland and 350 from the volcanic islands of Gomera and El Hierro in the Canaries. They are laid out according to criteria of similarity and difference, but not within rigid categories. The visual differences which are the basis of so much life speak by implication of the manifold variations in the lives themselves, of the wonderful attuning of plant physiology to minute variations in the compositions of soils.

On Closer Inspection (2000)
'On Closer Inspection' offers an opportunity to observe past achievements through the present. Drawing on the tradition of using botanical imagery as a source for decoration on china and porcelain, the artist produced magnified images of pollen grains as photographed through an electron microscope. The images have been used to develop a series of gilt prints, and they have been applied to a collection of bone china plates. A hole has been cut through each plate, and a magnifying lens has been inserted in it. The plates are positioned in front of, and partially obscure, objects relating to botanical history. Each lens becomes an animated screen, attracting the attention of the viewer in a tantalising way, and offering a magnified fragment of the object behind, whilst the rest is concealed.

 Mitosis (2002)
'Mitosis' comprises a group of blown-glass forms inspired by looking at images of plant cells in the process of dividing and splitting. A series of spheres have been blown and progressively stretched in their molten state until two new forms emerge. Here the artist's intention is not to provide scientific models but an artistic expression of a crucial moment of creation, frozen in time, and suspended in the fluidity of the cooled-down glass.

 The artist's approach to nature is marked by her longstanding observations and systematic visual representations of ever-changing natural phenomena. Derges' work represents the actual process of change. It is not intended to provide scientific proof, but rather to find internal parallels between different phenomena. Process per se, patiently and meticulously observed by the artist, becomes meaningful in itself, as a metaphor of the act of creation. Subjective and objective views cross fertilize in Derges' references to the world of nature and of science. She has, herself, experimented within nature's mysterious realm, exploring intensively such phenomena as powder on vibrating plates, arcs of water droplets, and the currents of river beds. For a time she kept bees, and observed their busy and intricate habits. She paralleled the insects' life and work cycle to that of a photographer, both working in the dark, and collecting and systematically storing elements from the outside world, and eventually processing and re-presenting these in new and intriguing combinations. Pollen Store was made during a time of bee-keeping and regular observation over a period of two years. Seasonal changes were recorded by the artist, and by the bees, respectively in her darkroom and in their pollen store. A single comb in the hive's brood chamber revealed colourful and abstract representations of the various materials that had been stored away throughout the seasons: blackthorn, hawthorn, dandelion, clover, heather and ivy, immortalised in hexagonal pockets of pollen. The work is rendered as a grid of 30 prints to echo the separate sections of the beehive.

 As artist-in-residence in the Museum of the History of Science in Oxford, Derges became interested in the history of alchemy, and early science. Ancient vessels used for alchemical purposes were accidentally discovered in the basement of the museum during building operations. These inspired her work, Vessel, in which processes and transformations are again the centre of her enquiry.

In parallel to narratives of distillation processes and the rotation of the elements, she made a sequence of images about the metamorphosis of frogspawn. She kept frogspawn and observed its development into tadpoles. She photographed the most significant points of change: the eggs, the embryos, in a crescent shape; the small tadpoles, swimming at the bottom of the vessel; the larger tadpoles, swirling at the centre of the container; the tadpoles with legs and tails, moving freely in the water; finally, the frogs, making their way up to the neck of the vessel, exiting from the image, concluding the cycle.

 The artist's work developed from an interest in family trees as the starting point for medical explorations of inherited disorders. Borland makes specific reference to cases depicted in a series of volumes published in the 1930s by the Galton Institute of Eugenics entitled "A Treasure of Human Inheritance". These are a collection of case notes and pedigrees relating to inherited conditions including Dwarfism, Colour blindness, Albinism and, most often, muscular and nervous diseases (Myotonic Dystrophy, Muscular Dystrophy and Huntington's Disease)

The studies of specific families were conducted mainly from the mid-nineteenth century to the early twentieth century. Successive generations are translated by the artist into a particular three dimensional configuration, in which each person is represented by a section of an agate stone. Although divided into groups of size and colour, each agate is unique in its configuration of crystals and rings. The different coloured agates represent various symptoms relating to the condition, in this case Huntington Disease - a hereditary degenerative disorder affecting movement, co-ordination and brain function. The family tree represented here covers five generations of the Entres family. The original case notes which provide the "key" - are presented on the adjacent wall.