Traces

by Patricia Wiltshire

  Twenty years after his wife’s disappearance, the publican died himself, and the son wanted a new start. He and his wife decided to refurbish the old pub, make it more popular and put some zing into the business. The barrel store with the disused mezzanine loft had always been a bugbear of his. He thought it was a waste of space and that it could be put to better use. The only way up into the loft was via an old ladder that had always been stacked behind the barrels. One weekend, after closing time, he decided to have a look at the state of the upper part of the building. He climbed the ladder but, as his eyes came level with the floorboards of the upper storey, what he saw shocked him so much that he nearly fell off. His mother had not run away after all.

  As it happened, when the body was discovered, I was in Gwent visiting my mother and her husband – the man she had married many years after she and my father had divorced. After two days of avoiding quarrelling with her, I was glad when the police rang. It was not too far to the pub and I could easily get there and back in a matter of hours.

  The publican’s son had found his mother as a mummified corpse, only a few feet from where the ladder was touching the floorboards of the loft. As I took my turn to climb the ladder, a grotesque picture greeted me. There was a grinning skull, wrapped in what looked like an old rug, and it seemed to be staring right at me. The forensic pathologist followed me up into a room which was shockingly neglected. Ivy was growing vigorously through holes in the roof and creeping along stacks of wood. Everything was overwhelmingly dirty and dusty, just like an exaggerated staged scene in a horror film.

  On the day she disappeared, she must have thought that life was not worth living and had crept up into the loft, lain down and swallowed as many pills as she could. The empty bottle was just beside her where she had dropped it as her hands went limp. Carefully placed at her side there was an old-fashioned, wide-necked milk bottle, still cloudy on the inside. Bizarrely, a pair of dentures lay deep in grime about a metre from her head. The pathologist suggested that, after taking so many pills and liquid, she had vomited violently before she died and her dentures must have shot out of her mouth. She was not wrapped in a rug – it turned out to be her woollen car coat and, pathetically, her head lay on a rolled-up sack. She had obviously not cared about comfort; she had just wanted to die and get away from all the strife in her troubled life. One could only wonder at the torment she suffered when alive. Like a wounded animal, she had crept away to die as anonymously as possible.

  The loft was incredibly dry considering there was a hole in the roof, and there was a continuous breeze wafting through. This had acted to dry her body quite quickly so that, instead of her belly becoming bloated and her skin and hair becoming wet and detached, she had slowly dried out and mummified. Now she was a desiccated, leathery version of herself. A good deal of information has certainly been derived from the body farms, but bodies seem to be predictable only in their unpredictability. After death, this woman’s decomposition had not followed the pathway I had seen in so many victims dumped in woodlands, ditches, or even left in armchairs. Her gut flora would have contributed to the decomposition of her internal tissues but, even inside, we later discovered the remains of her organs. Flies must have found her because there were some puparia around the body – but they had all hatched into adult flies and were long gone. Fairly quickly, she must have become too dry to tempt further egg-laying.

  The next morning, I arrived in the hospital mortuary in Cardiff for the mummified woman’s post-mortem. Every examination yields different information about the life and death of the dead person and, for a change, it was a relief to work on a corpse that did not stink. But the story of the suicide in the attic has a grisly coda. When she was opened up, the incredulous pathologist drew out what he believed to be a string of beads from inside the ribcage. I was almost as disbelieving at what I saw, even though I could identify it immediately. This was the desiccated gut of a rat still with its faecal pellets; they were regularly spaced like a string of beads, and this made it almost comical. I poked around a bit further up into the cadaver’s thorax and picked out a beautiful little rat skull.

  We can only theorise as to what had happened. It is possible that, by eating the flesh which, by this time, was saturated with barbiturates, the rodent had become poisoned too, and had died inside its cocoon of plenty. What was strange – really strange – was that we could not find any other rat bones. Where had the rest of the skeleton gone? Had some other scavenger, possibly a cat, found the rat in the cavity and made off with its booty, leaving just the head behind? It was a case of Russian dolls, one drama inside another, and another.

  Putrefaction can be delayed by any number of factors, natural and artificial. Poisons like arsenic and strychnine can arrest the decay, as can antibiotics and other medication, but the ambient environment at the time of death can also preserve soft tissue. Natural mummies like this might, given the correct conditions, last for thousands of years. In 1991, two German tourists were hiking along the Austrian-Italian border, through the Ötztal Alps, when they came across a mummified corpse preserved so perfectly that they presumed it belonged to a recently deceased mountaineer. The bottom of its body was frozen in ice, but above the torso, the man remained much the same as he was on the day that he passed on. When the mountaineers raised the alarm and the local gendarme arrived to recover the body, it was taken to a medical examiner in nearby Innsbruck – and it was here that the body was finally dated as being at least 4,000 years old.

  Ötzi, as the man came to be known, had lain here on the mountainside since the Neolithic period. He was a Stone Age man. The low temperatures and high winds had resulted in preservation of not only his tissues but also his clothes and footwear, his bow and arrows, the food in his pouch, and the fungus he had been carrying as tinder. Analysis of his stomach revealed his last meal, and the arrow, that has recently been shown to have caused his death, was still stuck in his shoulder blade. We only decompose if the environments inside and outside us favour the growth and activity of microorganisms. If they are inhibited, a mummy can form. Many such mummies have been found in the Steppes of Asia and in the mountains of South America, where conditions are too extreme to allow microbes to be active.

  If the stages of decomposition cannot be relied upon to give us accurate information about the timing of a person’s murder, then we must use other clues. And, in this, forensic ecologists have another important weapon in their arsenal. This weapon is a whole kingdom of organisms that evolved on Earth before the fish in the sea, insects in the air, or animals and plants on land. They are everywhere – in the soil, inside and outside plants and animals, colonising our countryside, our gardens, our homes – as well as in and on our own bodies. They have often proved to be the source of the most crucial information. These are the fungi.

  9.

  FRIENDS AND FOES

  I was educated in the botany department of King’s College London, and mycology (the study of fungi), and bacteriology, were two areas of study at which I excelled and most enjoyed. Traditionally, the fungi include mildews, moulds, blights, yeasts, lichens, rusts, smuts, slime moulds, and, of course, mushrooms. Until fairly recently, they were studied by botanists because they were thought to be plants and it was the Swedish botanist, Carl von Linné, in his two-volume Species Plantarum, published in 1753, who promulgated this monumental biological mistake. As he worked out the various groups of known living things, he put them into named categories. He decided that fungi were plants – and plants they stayed for 200 years, well into the 1960s. It was only then that we made the conceptual leap: fungi are now placed in their own kingdom, Fungi, while some blights and slime moulds have been moved out to the algae and protozoa, respectively.

  Fungi diverged from the rest of life about 1.5 billion years ago and recent molecular studies show that they are more closely related to animals than plants. They certainly feed in the same way. Like animals, they can only survive on food that has already been made, mostly by plants
or organisms that have, ultimately, fed on plant material. They are also like some animals in that digestion of their food occurs outside their bodies. The spider traps its fly, pours digestive enzymes onto it, and these dissolve the unfortunate prey into a mush. The spider then sucks up the liquid and discards the insect husk. Fungi do a similar thing and, indeed, some that live in the soil produce lassoes which catch tiny nematode worms. The fungus then grows throughout the worm and passes out enzymes to digest the prey’s tissues; these are broken down to molecules and are absorbed by the fungus into its own body. When a fungal spore germinates, it will develop a thin thread (a hypha), and this branches repeatedly to form a radiating, interconnecting mass of thin threads known as mycelium. A fungus has the advantage that it can push into, and through its food, as well as grow all over its surface. They are certainly not plants; plants use the magic molecule chlorophyll to trap the energy of sunlight and use it to convert carbon dioxide and water into sugar. Like all animals, in order to grow and reproduce, fungi need to feed on the living or dead tissues of other organisms.

  Fungi are very ancient indeed, but they do not fossilise well. Even so, there is some evidence of fungal-like organisms as far back as 2,400 million years ago. About 542 million years ago, and long before plants managaed it, they had colonised land from the sea. And, in the Silurian Period, starting about 444 million years ago, they were already highly diverse, occupying many ecological niches. To put them in context, fungi were well established about a billion years before dinosaurs first walked the earth.

  Taxonomists agree: we know most of the plants and animals – except for nematode worms and some insect groups such as beetles, whose number of species just keeps on growing – but the situation with fungi is more startling. With new molecular studies, it has been discovered that each fungal species that has been described probably consists of five or more species. Recently, one species of Aspergillus (a genus that includes serious human pathogens) was analysed and found to be 47 kinds of organism, each with different potential. The scale and diversity of the fungal kingdom is vast, and as yet we know barely 5% of the species sharing the planet with us.

  Plants build up and fungi break down. Fungi are the principal agents of the degradation of plant material. Indeed, they are the only ones that can break down the lignin, the complicated polymer, that makes wood hard, but they also play some role in the decomposition of all dead things. Where dead things lie, the fungus feasts. If it did not, and there were no breakdown, all the chemical building blocks of life would remain locked up forever in the dead bodies of plants and animals, including those of humans. If this were to happen, nothing could ever be born and life would come to a standstill. Decomposition is utterly essential if we are to have any life at all. Living things are constantly being recycled and, eventually, that will include you and me.

  Until recently, forensic scientists believed that the only way fungi could be used in their investigations was in cases of poisoning, or the illicit use of psychotropic (hallucinogenic) species. But what fungi present is actually a much richer cache of information. The way they grow, the rate they grow, the patterns their growths make – all of these can be recorded and interpreted to help the canny observer put a certain person in a certain place at a certain time, to estimate the length of time that has elapsed since a victim drew his last breath, to ascertain the actual cause of death. Like pollen, fungi leave their testimony wherever they grow.

  Fungi can be microscopically small and improbably vast. The hyphae germinate from microscopic spores and these threads aggregate to form the spreading, interconnecting, and outwardly ramifying fungal mass of mycelium. These threads only stop when they meet a barrier or run out of food. If there is nothing to prevent it, and it can scavenge food, the mycelium can spread for miles and miles for very many years. There have been several reported huge colonies of species of Armillaria (honey fungus) in North America, but the record holder for the largest is a giant Armillaria ostoyae, discovered in 1998 in the Malheur National Forest in Oregon. Based on its current growth rate it is estimated to be about 2,400 years old and could be as much as 8,650 years old. It covers nearly four square miles and, as it radiated out from the point where a microscopic spore germinated, it killed trees and then fed on them so that it was never short of food. Besides the dead trees, its presence is revealed by honey-coloured mushrooms – pretty masses emerging from the base of the tree trunk.

  This is one of the world’s vast fungi. But the black mould, Cladosporium, growing between the tiles of a poorly ventilated bathroom is a fungus as well. So are the green and white patches that appear on a loaf of bread you have left uneaten for too long, or the variously coloured greens that appear on an orange left uneaten at the bottom of the fruit bowl. The yeasts that bakers add to flour and water to make bread, or that brewers use to make beer – these too are fungi. Without fungi, we would have few antibiotics, no fizzy lemonade, biological soap powders, tea, coffee, trees, flowers, most foodstuffs in the larder, and many essentials in our modern lives. Even many animals that we eat would not thrive without the fungi in their guts, and the grass would not grow for them to eat in the first place. We are surrounded and penetrated by fungi and we cannot survive without them. We feed them and they feed us.

  Wherever there is digestible food to be found, fungi will follow. A single teaspoon full of soil from the top of the earth’s crust can contain more than 100,000 viable spores and little bits of fungus, each one capable of making a colony. Think of this the next time you look out of the window and really consider the world around you. Our own bodies, and most mammals, are covered in yeasts, such as Malassezia, which does not usually do any harm, although one species is the most common cause of dandruff. And, of course, many people are aware of the thrush fungus, Candida, which can cause irritation but, on some rare occasions, death, should it get into blood and internal organs. Most people get some sort of fungal infection in their life. If you’ve ever had athlete’s foot, you will have been colonised by a species of Trichophyton, or possibly Epidermophyton floccosum. These are common soil organisms so it is sensible to protect the feet when working in, or walking on, bare soil because these fungi can make the foot (usually between the toes) very sore and scaly. When Trichophyton causes circular patches of red, sore, scaly skin anywhere else on the body, even the scalp, it is called ‘ringworm’ – although, of course, no worm is involved. Fungi are notoriously difficult to get rid of because most of the medication that will kill them will kill you too. Bacterial infections are fairly easy to dispel because bacteria are so different from us in every way, but fungi are more closely related to us, and we share some of their sensitivity to certain toxins.

  If the living human body, with all of its defences and immune system in good order, can provide such a fertile habitat for fungi, what then of the body after it is dead? To many species of fungus, a human corpse is a vast source of nutrients waiting to be digested. And in one particular case that has always lodged in my mind. It was the way in which fungi had feasted and spread upon a murdered man’s carpet and sofa that eventually contributed to confirming his killer.

  Picture a block of flats in a dismal, wintry Dundee. Picture a front door forced open by police after someone has reported their friend missing. See a man lying spread-eagled, his face pressed into the carpet, and the multiple stab wounds – no mystery at all around the cause of death.

  Now picture the blood and other body fluids that have splashed on the furniture as they spurted out of the stab wounds, and then oozed out of him, soaking into the carpet. Windows are closed and the flat is incredibly hot because the central heating has been blasting out for some time. The blood spatter is highlighted by grey, white, green, and brown growths of fungi whose spores, lying dormant in the furnishings, have been kissed awake by the sudden provision of all this food. Until now, the flat has remained closed; the corpse has been protected from scavengers, and the flies which might otherwise have come and laid eggs in its orifices. Fungi
have spread wherever there was food – but, now that the blood and bodily fluids have dried up, or been entirely used by the fungus as it spread, its growth has come to a halt. The colonies are like an atlas on the carpet, marking the shorelines and boundaries where the dead man’s blood has reached.

  This was the scene that faced me when, in 2009, my husband David and I caught the night flight to Dundee and arrived at the dead man’s flat. One of the police officers had been told that fungi could be used to estimate the timing of events and, bright chap that he was, recommended to the Senior Investigating Officer to get us to the scene.

  We often get weird and wonderful puzzles to solve, and the key to deciphering what had happened here was the extent the fungus had grown in the blood that had spilled from the man’s wounds. The first thing to do was decide on a representative sample area, take photographs, and draw diagrams of the colonies within it. I then cut out representative pieces of the sofa cushions and the carpet, and put them into sterile plastic containers. By telephone, we had already asked for humidity and temperature to be monitored, and a substantial record for the flat was already available. It confirmed that the average temperature had been about 26oC and the relative humidity about 34%. Lovely and warm for fungal growth, but definitely too dry – most fungi need a relative humidity of around 95% to grow at all. You will know this from your own home. If you get a leak from the roof, the wallpaper will soon go black and green with fungal growth. Where you have mould growth, you have damp. What this meant, here in the flat, was that until the dead man’s blood had splashed out over the carpet, there had not been enough moisture for the spores, dormant in the carpet and furniture, even to germinate. Then a bonanza of food and water had become available.