CHAPTER ONE
IN SEPTEMBER 1991, hikers in the Tyrolean Alps made a remarkable discovery. On a steep, rocky ridge at 10,500 feet above sea level, they found a 5,300-year-old mummy, the oldest intact human being ever discovered. The Iceman, as he came to be known, yielded much information about the neolithic period in which he lived. He carried a copper axe. Previous to the Iceman’s discovery, scientists believed that humans were smelting and shaping copper 4,000, not 5,300, years ago. Also, he may have undergone a treatment resembling acupuncture. The tattoos on his legs and back were on or near the acupuncture points for treating arthritis.
To mycologists, the botanists who study fungi, the most interesting aspect of the Iceman was his medicine kit. Strung to a leather thong, he carried, two walnut-sized dried fungi that researchers have identified as Piptoporus betulinus. The fungus is known for its antibiotic properties. When ingested, it can bring on short bouts of diarrhea. Researchers determined that the Iceman suffered from intestinal parasites. He probably used the Piptoporus betulinus in his medicine kit as a natural worm-killer and laxative.
If the Iceman is any proof, neolithic Europeans used mushrooms for their medicinal qualities. Still, as this book will show, the use of medicinal mushrooms in Europe pales when compared with their use in China and Japan. Except in myth and folklore, mushrooms for medicinal purposes were nearly unknown in Western culture. Only in recent years has the West awakened to the medicinal benefits of mushrooms. What accounts for the widespread interest in mushrooms in the East compared to the West?
Of all cultures, mushrooms are perhaps least valued in the West, especially in regard to their use as medicine. Egyptian hieroglyphics dating to 4,600 years ago show that the pharaohs believed that mushrooms were the plant of immortality. The ancient Egyptians believed that mushrooms growing in the wild were the “sons of the gods” who had been sent to earth on lightning bolts. As such, only the pharaohs were permitted to eat them. The sixteenth-century missionary Bernardino de Sahagún reported that the Aztecs ate a sacred mushroom called teonanacatl, which he translated to mean “flesh of the gods.” In ancient China, the emperors decreed that all Reishi mushrooms, which were valued as the preeminent tonic herb, be handed over to them (reishi is covered in Chapter Three of this book). Why, then, have mushrooms been neglected in the West?
Until well into the Renaissance, Europeans looked to the ancient Greeks and Romans for their ideas about treating illnesses, and Greek and Roman physicians had little to say about the medicinal qualities of mushrooms. The Roman encyclopedist and naturalist Pliny (23–79 C.E.) described several types of fungi but did so inadequately—it is hard to tell which species he refers to in his writings. The first western pharmacopoeia, De Materia Medica, an authority in Europe for 1,600 years, ascribes healing properties to only a single mushroom. Dioscorides (circa 40–90 C.E.), the author of De Materia Medica, offers this general description of mushrooms:
... either they are edible, or they are poisonous, and come to be so on many occasions, for either they grow amongst rusty nails or rotten rags, or ye holes of serpents, or amongst trees properly bearing harmful fruits. Such as these have also a viscous concreted humor, but being laid away after they are taken up, they are quickly corrupted growing rotten. But they which are not sod in broth are sweet, yet for all that, those taken too much do hurt, being hard of digestion, choking or breeding choler.
The Roman philosopher Seneca wrote of mushrooms: “(They) are not really food, but are relished to bully the sated stomach into further eating.” Diderot in his Encyclopédie wrote, “Whatever dressing one gives to them, to whatever sauce our apiciuses put them, they are not really good but to be sent back to the dung heap where they are born.”
The aversion to mushrooms was pronounced in England and Ireland, where the inhabitants as a rule did not eat them or use them as medicine. “Most of them do suffocate and strangle the eater,” wrote John Gerard in The Herball or Generall Historie of Plants, a compendium of the properties and folkore of plants that was published in 1597.
“Treacherous gratifications,” wrote John Farley about mushrooms in The London Art of Cookery, published in 1784.
The English physician Tobias Venner wrote about mushrooms in 1620, “Many phantasticall people doe greatly delight to eat of the earthly excrescences called Mushrums. They are convenient for no season, age or temperament.” Venner is remembered today as the author of the first tobacco warning label. “Tobacco,” he wrote in Via Recta, “drieth the brain, dimmeth the sight, vitiateth the smell, hurteth the stomach, destroyeth the concoction, disturbeth the humors and spirits, corrupteth the breath, induceth a trembling of the limbs, exsiccateth the windpipe, lungs, and liver, annoyeth the milt, scorcheth the heart, and causeth the blood to be adjusted.”
In “Mont Blanc” (written in 1816), a poem that explores the relationship between humankind and nature, Percy Bysshe Shelley paints a vivid picture of mushrooms growing on the forest floor—and he reveals the prejudices of his time and place against mushrooms:
And plants at whose name the verse feels loath,
Fill’d the place with a monstrous undergrowth,
Prickly and pulpous, and blistering, and blue,
Livid, and starr’d with a lurid dew,
And agarics, and fungi, with mildew and mould,
Started like mist from the wet ground cold;
Pale, fleshy, as if the decaying dead
With a spirit of growth had been animated.
Their mass rotted, off them flake by flake,
Till the thick stalk stuck like a murderer’s stake,
Where rags of loose flesh yet tremble on high,
Infecting the winds that wander by.
Not all European countries are as mycophobic as the English. In Italy, Poland, and much of Eastern Europe and Russia, mushrooms are an important part of the diet, and the first days of spring find whole families journeying to the countryside to harvest mushrooms. Generally speaking, countries that underwent rapid industrialization are more likely to be mycophobic. In those countries, where industrialization often displaced the rural population, knowledge of native mushrooms and plants is more likely to be lost. In countries with stable rural popUlations, mushroom lore can be handed from generation to generation as youngsters forage in the company of adults.
Almost everyone is the descendent of immigrants in the United States. For that reason, knowledge of native mushrooms cannot have been handed down in a steady line from one generation to the next. Most Americans are strangers to their mushrooms. That, more than any other reason, explains why Americans are mycophobic. The first and sometimes only thing American children learn about wild mushrooms is that some are poisonous and therefore you should never pick or eat one.
Because mushrooms usually grow in the shadows, in damp places, and in decay; because they look strange and have no counterpart in nature; they were sometimes associated with demons and spirits. The strange excrescences of the forest literally appear overnight—a fantastic occurrence that could only be the work of devils. In medieval times, it was believed that thunder caused mushrooms to sprout in the forest. Many believed that devils and witches used mushrooms to cast spells.
Indeed, the ergot fungus was probably the catalyst for witch trials throughout the Middle Ages, not that the witches’ accusers understood why. When the ergot fungus (Claviceps purpurea) invades rye and conditions are appropriately damp, peasants who eat the fungus in their rye bread may suffer from ergotism. Because wheat was highly sensitive to diseases, rot, fungal infection, and harsh weather, rye was the grain of choice among the poor masses. Bread was the principle diet in many parts of Europe during the Middle Ages, when people are supposed to have eaten a pound and a half of bread a day, making them especially susceptible to ergotism.
Ergotism causes blisters on the skin, feelings of being pricked, and burning sensations. In extreme cases, sufferers experience convulsions. They have vivid hallucinations. The flow of blood to the limbs is constricted, and limbs may turn gangrenous and fall off. Some scholars blame an outbreak of ergotism for the Salem, Massachusetts, witchcraft trials of 1692. Interestingly, a handful of scholars also argue that ergotism helped launch the Great Awakening of 1741, a religious revival that swept across New England and had participants experiencing visions and trances. In 1943, the Swiss chemist Albert Hoffman, experimenting with ergot alkaloids, discovered LSD.
Two prominent figures of history were killed by mushroom poisoning and their deaths may have contributed to the reputation of the mushroom as a dangerous poison. In 54 C.E., Emperor Claudius of Rome was poisoned by his fourth wife, Agrippina. He is supposed to have died a painful death twelve hours after eating poisonous mushrooms. The Buddha is supposed to have died by a mushroom he believed to be a delicacy. The mushroom was offered as a gift and is said to have been a type that “grew underground,” although nothing more is known about it. (However, some scholars believe that the Buddha died from choking on pork, not from eating a poisonous mushroom.) The first known written reference to eating mushrooms is an epigram written by Euripedes in about 450 B.C.E. It tells of a woman and her three children who died from mushroom poisoning.
To be fair to Europeans, mushrooms may have been a part of European medicine in the past. The records are hard to come by because folk medicine was not recorded or valued during the Middle Ages in the same manner as in ancient Greek and Roman medicine. What’s more, Christian church officials, operating under the notion that folk healers were pagan practitioners of heathen religions, suppressed folk medicine and sometimes persecuted those who practiced it. Very little research into medicine was recorded during the Middle Ages as the monks busied themselves with copying and recopying Greek and Roman medical texts. Then, with the coming of the Renaissance, European physicians took what they believed to be a more scientific approach to their work. Folk remedies were considered backward and were shunned in favor of contemporary medicines and treatments.
All this is not to say that fungi are not used as medicine in the West. Consider these three important drugs, all of which are derived from fungi:
As to culinary mushrooms, the prejudice against them may be subsiding in the United States. The bland button mushroom still accounts for the majority of mushroom sales, according to the American Mushroom Institute, but sales of shiitakes, oyster mushrooms, and other more exotic culinary varieties are on the rise. Between 1989 and 1995, sales of shiitake mushrooms doubled. Sales of oyster mushrooms grew by 36 percent. Overall, mushroom sales grew by 25 percent. Black and white morels, porcinis, chanterelles, portobellos, and enokis are now available in some gourmet markets and sometimes in supermarkets as well.
In recent years, R. Gordon Wasserman, Albert Hoffman, Carl A.P. Ruck, and other scholars have proposed that ancient Greeks and Romans used hallucinogenic mushrooms in their religious rituals. Because the rituals were conducted in private and the participants were sworn to secrecy, the evidence is hard to read. But Wasserman and others make compelling arguments for the use of hallucinogenic mushrooms by Greeks, Romans, and even early Christians.
In Greek mythology, Demeter’s daughter Persephone was kidnapped by Pluto, the king of the Underworld. Furious, Demeter killed all the crops, whereupon Zeus, afraid that his subjects would starve and no one would be left to make sacrifices, brokered an arrangement: Persephone would spend a third of the year in Hades with Pluto and the rest of the year above ground with her mother. The myth celebrates birth and regeneration, the return of spring, and the blessings of agriculture.
Annually, the Greeks held a festival in October to commemorate Demeter’s reunion with Persephone. For several days, revelers filled the streets of Athens, and then the festival moved to nearby Eleusis, where a select few were allowed in the initiation hall. There, in the semidarkness, they drank a potion called kykeon (“mixture”) and beheld the Mysteries of Eleusis. Initiates are supposed to have experienced convulsions and hallucinations. In an anonymous seventh-century B.C.E. poem describing the mysteries, the poet speaks of seeing the beginning and ending of life, a vast circle starting and ending in the same place.
Kykeon was made of barley, water, and mint. Wasserman and his colleagues believe that ergot-infested barley accounts for the hallucinogenic nature of the potion. To back up their theory, they point out that kykeon was purple, as is ergot sclerotia when immersed in water. Purple, the color of ergot, was also Demeter’s identifying color, and an ear of grain was the symbol of the Eleusinian Mysteries.
We will probably never know whether drinking ergot was a feature of the Eleusinian Mysteries. Nevertheless, it is intriguing to think that Socrates, Plato, and other seminal thinkers of Western philosophy drank ergot, the fungus from which LSD is derived, during the festival of Eleusis.
No less a scholar than Robert Graves has suggested that followers of the Dionysus cult ate the hallucinogenic mushroom Amanita muscaria during their autumnal feasts. A mosaic in the ancient Christian basilica of Aquileia in northern Italy clearly shows a basket filled with Amanita muscaria mushrooms. Some scholars have suggested that early Christians ate the mushroom in their religious rituals, but the mosaic at Aquileia may well be left over from the original Roman temple, the one from which the basilica was built.
The ritual use of the hallucinogenic mushroom Amanita muscaria by shamans and priests in Asia, America, and Africa is well documented. The priests of ancient Europe could well have used the mushroom in their rituals, too. The Vikings are supposed to have eaten it before battle to induce the “berserk” state and make themselves more ferocious to their enemies. The renewed interest in mushrooms in the West has inspired scholars to look into whether ancient Europeans used Amanita muscaria, and we look forward to more scholarly research in this area.
The Koryak tribe of Siberia are not Europeans, but their use of Amanita muscaria is too interesting not to relate. Filip Johann von Strahlenberg, a Swedish explorer traveling in Siberia in the early 1700S, records how wealthy tribe members assembled in a hut to ingest the mushroom, while the tribe’s poorer members, not to be denied the experience, assembled outside. When an intoxicated tribe member left the hut to urinate, those outside gathered around to collect his urine in a bowl so that they could drink and partake of the hallucinogenic mushroom, albeit secondhand.
Chinese culture is anything but mycophobic. The prejudice against fungi is entirely absent in China. The Chinese faith in the medicinal qualities of mushrooms is unimpeachable. As anybody who has eaten in a Chinese restaurant knows, mushrooms are a feature of Chinese cuisine. Gathering mushrooms is a popular pastime in the countryside. In China’s oldest materia medica, the Herbal Classic, many mushrooms are described, so the use of mushrooms for medicinal purposes in China reaches far into the past. (Legend has it that the Herbal Classic was written in the twenty-eighth century B.C.E. by emperor Shen Nung, the Divine Plowman Emperor, but most scholars date the book to about 200 C.E.)
Why were (and are) mushrooms valued in the East, but not the West, for their medicinal properties? One can only speculate on this subject, but here are a few possibilities as to why the Chinese value medicinal mushrooms so highly:
Throughout this book, we describe how traditional Chinese medicine prescribes mushrooms to treat different ailments. Because most people who read this book are strangers to traditional Chinese medicine, a few words about it are in order.
The traditional Chinese system represents a completely different medical language. It has been said that traditional Chinese medicine attempts to understand the body as an ecosystem or single component in nature. Whereas a Western doctor studies a symptom in order to determine the underlying disease, a Chinese doctor sees the symptom as part of a totality. Western medicine is concerned with isolating diseases in order to treat them. Traditional Chinese medicine seeks a “pattern of disharmony,” or imbalance, in the patient.
The principles of traditional Chinese medicine can be found in Taoism, the ancient philosophy or religion in which the practitioner strives to follow the correct path, or Tao, and thereby find a rightful place in the universe. Taoists believe that the universe is animated by an omnipresent life-energy called Qi (pronounced CHEE). Qi, meanwhile, comprises two primal opposites, yin and yang. The yin and yang complement each other and are always interacting. They produce change in the universe. They counterbalance each other. Yin, the negative balance, represents water, quiet, substance, and night, among other things. Yang, the positive balance, represents fire, noise, function, day, and other entities. The interplay of yin and yang keeps the universe alive and vital.
In a healthy human body, Qi circulates unimpeded and the balance of yin and yang is maintained, but an excess of yin or yang or a blockage of Qi can create a pattern of disharmony and render the patient ill. No disease has a cause according to traditional Chinese medicine. Rather, disease is a malevolent configuration of yin-yang forces in the body.
Qi flows through the body in invisible channels called meridians. In their diagnoses. acupuncturists examine the body’s meridian points, the places where Qi is concentrated. If they discover that the body’s Qi is congested or needs redirecting, they insert a pin in the proper meridian point.
In keeping with the Taoist idea that the body is a small-scale representation of the cosmos, much of the medical terminology is based on the workings of nature. Physicians examine patients for dampness, wind, cold, dryness, and summer heat. As nature is organized into five primal powers (water, fire, wood, earth, and metal), the body is regulated by five organ networks (kidney, heart, spleen, liver, and lung), each with its own yin-yang energy.
Traditional Chinese medicine encompasses four different ways of treating the sick:
Entering into the thought-system of traditional Chinese medicine is not easy for a Westerner. The terminology can be baffling. The system takes ideas and principles that are foreign to Western thought as its premise. To explain the success of traditional Chinese medicine in healing the sick and preventing illness, some in the West dismiss Chinese medicine by crediting its success to the placebo effect. Others take the opposite tack and see traditional Chinese medicine as a sort of faith-based religion. They believe that Chinese medicine, because it is ancient and has roots in the East, is more spiritual and therefore more beneficial than Western medicine.
But traditional Chinese medicine is medicine. However strange it may appear to Westerners, traditional Chinese medicine represents the culmination of four thousand years of clinical practice and observation. Like Western medicine, traditional Chinese medicine is an ever-evolving attempt to understand how the body works, how disease affects the body, and how to treat and prevent illness. Although the underlying philosophy is different from Western medicine, the perception of health and illness that traditional Chinese medicine upholds is valid and true to itself.
After the Chinese revolution of 1949, the communist government considered abandoning traditional Chinese medicine. The idea was to embrace Western medicine as part of the campaign to modernize China. Some in the government considered the Chinese brand of medicine backward, a remnant of underdevelopment. To see whether traditional Chinese medicine had any value, the government sponsored numerous clinical studies and tests starting in the 1950S (some of these tests were the first undertaken on medicinal mushrooms). The government’s conclusion: Traditional Chinese medicine works clinically and should be given equal footing with Western medicine.
Acupuncture, the most popular brand of traditional Chinese medicine in the West, received a big boost in the United States in 1971 when New York Times reporter James Reston, accompanying Secretary of State Henry Kissinger on a trip to Beijing, needed an emergency appendectomy. Reston was treated for postoperative pain with acupuncture, a much-publicized event that put the spotlight on acupuncture as a means of relieving pain. (The focus on acupuncture as an analgesia and anesthetic continues; the clinical benefits of acupuncture are not as well understood or appreciated in the West.) Wrote Reston:
In brief summary, the facts are that with the assistance of eleven of the leading medial specialists in Peking (Beijing), who were asked by Premier Chou En-lai to cooperate on the case, Prof. Wu Wei-jan of the Anti-Imperialist Hospital’s surgical staff removed my appendix on July 17 after a normal injection of xylocaine and benzocaine, which anesthetized the middle of my body.
There were no complications, nausea, or vomiting. I was conscious throughout, followed the instructions of Professor Wu as translated to me by Ma Yu-chen of the Chinese Foreign Ministry during the operation, and was back in my bedroom in the hospital in two and a half hours.
However, I was in considerable discomfort if not pain during the second night after the operation, and Li Chang-yuan, doctor of acupuncture at the hospital, with my approval, inserted three long thin needles into the outer part of my right elbow and below my knees and manipulated them in order to stimulate the intestine and relieve the pressure and distension of the stomach.
That sent ripples of pain racing through my limbs and, at least, had the effect of diverting my attention from the distress in my stomach. Meanwhile, Doctor Li lit two pieces of an herb called ai, which looked like the burning stumps of a broken cheap cigar, and held them close to my abdomen while occasionally twirling the needles into action.
All this took about twenty minutes, during which I remember thinking that it was a rather complicated way to get rid of gas in the stomach, but there was noticeable relaxation of the pressure and distension within an hour and no recurrence of the problem thereafter.
Practitioners of traditional Chinese medicine are now found in most major cities in the West, and not just in the Chinatowns of major cities, either. Nearly thirty American states license or certify acupuncture practitioners. In the United States, approximately 10,000 nationally certified acupuncturists were practicing in the year 1995. Over five million Americans visited acupuncturists in 1997.
As the interest in preventative medicine, natural medicine, and non-drug therapies increases, so does the interest in traditional Chinese medicine. Colleges for its study have been established in France, the United States, Italy, and Australia. In Germany, the University of Münich sponsors an institute for the study of traditional Chinese medicine. This kind of cross-cultural scholarship is bound to open new doors and yield many exciting discoveries.
What we call a “mushroom” is the fruit-body of a fungus. In other words, the mushroom is the reproductive part of the fungus that grows above ground and releases spores, the seedlike elements from which new fungi are made. Much as fruit is the reproductive organ of a fruit tree, a mushroom is the reproductive organ of a fungus. Not all fungi, however, produce mushrooms. Some are able to create spores and reproduce without bearing a fruit-body. Fungi that reproduce without a sexual stage are called imperfect fungi, or fungi imperfecti.
In nature, fungi are the great recyclers. To feed itself, but also to assist plants in getting the nutrients they need, a fungus breaks down organic matter into essential elements. There are about a hundred thousand species of fungi and 38,000 mushroom species. About seven hundred species are eaten as food. Fifty or so species are poisonous. Fungi make up about a quarter of the biomass of the earth. Strange as it may seem, seeing as they are usually associated with rot and decay, fungi are something of a cleanser in that they transform dead organic matter into nutrients that plants and animals can feed on. Without fungi, matter would not break down and decompose. The world would be crowded with dead animals and plants. The odor from so much unregenerated decay would be dreadful.
Every fungus begins as a tiny, seedlike spore. Spores are carried by wind and water. When a spore lands in a hospitable place—a moist place that is not too hot or cold and is near a food source—it may germinate and start a new fungus colony. At that point, the spore grows hyphae, the fine, threadlike strands from which the mycelium is made.
The mycelium is the feeding body of the mushroom. Composed of a latticework of interconnected hyphae threads, it is for the most part subterranean, living in soil or decayed wood, much like the root system of a plant. It can feed on almost any organic substrate: soil, wood rot, food left for too long in the pantry. How fast and how large the mycelium grows depends on environmental factors such as soil temperature and the accessibility of food. Researchers have reported finding a mycelium beneath the soil of Michigan that is 1,500 years old and thirty-five acres wide, and weighs a hundred tons. This mycelium is from the fungus Armillaria bulbosa, a root pathogen of Aspen. Using molecular methods, the researchers mapped the extent of the fungus genome to show that the mycelium germinated from a single spore. In case you’re in the neighborhood, the researchers place the monster on the upper peninsula of Michigan at 45°58’28" N longitude, 88° 21’46" W.
The mycelium insinuates itself into the substrate on which it feeds. It secretes complex enzymes that break down organic material in such a way that the fungus can absorb food from the substrate. Research has shown that these complex enzymes act as a growth stimulus to plants. They degrade organic material so that important nutrients are returned to the soil where plants can feed on them. In this way, fungi provide the raw material for trees and plants.
Fungi are essential for a healthy forest. If there are no fungi in the soil, plants cannot grow as they cannot break down and absorb nutrients without the help of fungi. One group of mushrooms, called the mycorrhizae, attach themselves to the roots of trees. They act like a secondary root system, reaching deep into the soil to get nutrients that the tree could not otherwise get and passing these nutrients upward to the tree. In return, trees provide the mycorrhizal fungus with a set of nutrients that they need to grow. The fungus and tree work together in a symbiotic partnership.
In effect, fungi are molecular disassemblers. They take the complex compounds created by plants, such as cellulose, carbohydrates, and protein, and disassemble those compounds so that plants can digest them. By contrast, plants are molecular assemblers. They take very simple compounds such as water, nitrogen, and carbon and combine them into complex forms such as protein, carbohydrates, and cellulose.
Some scientists believe that the ability of fungi to break down organic matter is linked to the antidisease properties of fungi. Fungi live in a hostile environment amongst decay on the harshest layer of the ecosystem. There, they encounter disease-causing pathogens far more frequently than other life-forms. To survive, they must have proactive, healthy immune systems. Some scientists believe that the antipathogen properties in mushrooms are precisely what make mushrooms valuable to the human immune system.
To ensure its survival, every fungus produces spores, the incredibly light agents of fungal reproduction. In most fungi, spores are produced in the fruit-body, the mushroom part of the fungi that grows above the soil. Typically, spores sprout from the gills, the thin brown tissue found on the underside of the cap. Borne by the wind, some kinds of spores are capable of traveling great distances from the fruit-body to start their own fungus colonies.
Mushrooms produce prodigious numbers of spores. A giant puffball, for example, may produce 20 trillion. The spores are produced in such large numbers to guarantee the spread of the fungus in the environment. The mycologist Elio Schaechter has written about spores, “Lavishness is necessary; rare is the spore that germinates into successful fungal growth. Such wastefulness, however, is not unlike the production of millions of unsuccessful sperm cells by the human male.”
Fungi, in their own small way, may exhibit a primitive intelligence. How else can one explain advanced behavior on the part of certain fungi? To make the case for fungi being intelligent, we present Cordyceps curculionum and the amoebalike slime mold Physarum polycephalum.
Cordyceps refers to different varieties of fungi that grow and feed on the bodies of insects. (Chapter Four of this book describes Cordyceps sinensis, a mushroom that grows from the bodies of caterpillars in the mountains of China and Nepal.) In the case of Cordyceps curculionum, the spore attaches itself to an ant, germinates, begins feeding, and grows into a small mushroom. The ant, meanwhile, with the mushroom riding piggyback, goes about its normal business. One day, however, the ant is seized with a sudden desire to climb a tree, and up it goes. When it reaches a height sufficient for the release of the Cordyceps curculionum spores, the ant digs its mandibles into the tree and remains there for the rest of its life. When it finally dies, the spores are released from on high and are spread far and wide on the forest floor. Cordyceps curculionum shows admirable restraint by not eating the ant right away. Its display of moderation in the presence of food seems to demonstrate a level of intelligence that isn’t present in a few people we know.
To test the intelligence of the slime mold Physarum polycephalum, Toshiyuki Nakagaki of the Bio-Mimetic Control Research Center in Nagoya, Japan, placed pieces ofthe mold in the middle of a five-square-inch maze. In the two exit points of the maze, he placed a food source, ground oat flakes. The idea was to see whether the fungus would abandon its normal method of foraging for food—by spreading outward from a central point of germination—and instead grow directly toward the food sources. To his surprise, Nakagaki discovered that the mold did indeed go straight toward the food sources. The organism stretched itself in a thin line along the contours of the maze until it reached the exit points. Similar to a laboratory rat, the slime mold was able to negotiate the maze and find the source of food.
By navigating the maze, Physarum polycephalum demonstrated a kind of intelligence that is not usually found, for example, at shopping malls. Mall shoppers are known to wander aimlessly in the shopping maze until they arrive by accident at the thing they want. Physarum polycephalum knows how to get there straightaway.