Here's one way it might have begun:
A tiny yellow speck drifts weightlessly on a warm spring breeze, floating in a neither-here-nor-there state, that "hungerless sleep" of a spore. The wind pushes the spore this way and that. It lights onto an oak leaf and is shaken free, comes to rest on a twig of poplar, then tumbles loose and resumes its aimless flight. A sharp gust propels it against the branch of an American chestnut tree. As chance would have it, the bark is cracked from the slight scratch of a squirrel's sharp claw. The spore slips into the crevice. With awful randomness, all the elements have conspired to deliver the spore just where it needs to be. Now, like a spark dropped onto a pile of dry brush, it flares to life.
On a hot summer day in 1904, Hermann Merkel, chief forester for the New York Zoological Park (now known as the Bronx Zoo), stood puzzling over one of the park's American chestnut trees. The other trees nearby wore healthy crowns of green, but this tree did not. Several branches were dangling withered brown leaves, as if autumn had arrived a few months too early. And it wasn't the only ailing chestnut.
In recent months, several in the park had suddenly and mysteriously begun to die.
Merkel was bewildered and concerned. The chestnuts were prized trees in the native forest that was the pride of the newly established Zoological Park. The woods were dense with chestnuts, oaks, birch, dogwoods, locusts, pines, poplars, and other trees and shrubs that had been carefully protected and preserved for more than eighty years by the former owners, a prominent New York family. In building the park five years earlier, the Zoological Society had been determined to give as much attention to landscaping as to the animal collection. There would be a formal concourse to mark the entryway, but the rest of the park was "as far as possible [to] be kept in its natural condition." Only native flora were to be planted on the grounds; those seeking exotica would have to head across the road to the city's other newly created natural attraction, the New York Botanical Garden. Merkel, a German native who probably had learned his trade from the famed foresters in his homeland, was well suited to the task of maintaining the landscaping. He and his crew worked hard clearing dead brush from the woods, planting thousands of new trees and shrubs, sowing flower beds with perennials, and placing fast-growing maples and poplars in unshaded spots. By 1904, more than a million visitors a year were making their way by carriage, train, or the recently completed subway to the city's latest must-see destination. There they could spend a day wandering the verdant grounds and touring an assortment of rare and wondrous beasts and birds. The collection included chimpanzees, two snow leopards, an Indian elephant named Gunda, a Malayan sun bear, and a small herd of American bison, whose beleaguered species the zoo's director was determined to save from obliteration. On sweltering summer weekends, the park drew residents of Manhattan's crowded Lower East Side tenements; they'd camp out in the cool shade of the hemlock grove "where lines of laundry could often be seen hung out to dry."
But now something was undoing Merkel's hard work. Could insects be responsible? That didn't appear to be the case. On close inspection of the ailing chestnuts, Merkel noticed unusual marks on their trunks and branches: a ring of dry bark around the affected branch and a peppering of minute orange dots. It looked like some kind of fungus, though not one he had ever seen before. He decided to treat the trees with a fungicide and keep his eyes on them.
By the following spring, Merkel knew he had a serious problem on his hands. Nearly every chestnut tree in the park was infected, from stately elders to twiggy young sprouts. Merkel sent off samples of diseased bark and a plea for help to the U.S. Department of Agriculture (USDA) in Washington, D.C. The agency had no experts in forest diseases on staff; it would be another two years before it established a formal lab to deal with such problems. So the sample was given to Flora Patterson, an expert on mushrooms and fungi. She was blasé. There was nothing mysterious here, she declared: the culprit was a common canker-causing fungus called Cytospora. True, Cytospora had never been known to harm chestnut trees, but she saw no cause for concern. Cut off the affected branches and burn them, she advised. Then spray the trees with "Bordeaux mixture," a powerful concoction of lime, salt, and copper sulfate that the French had used to successfully combat a fungal disease afflicting their grapevines.
With an emergency appropriation of two thousand dollars, Merkel set about trying to treat his sickened trees. The task was immense, and his crew of foresters and tree surgeons worked late into the summer nights to get the job done. They cut away diseased branches from 438 chestnuts. Sometimes the infection was so widespread they had to amputate every limb off a tree, leaving only a woeful-looking bare trunk. So many trees needed to be sprayed that Merkel brought in a power-spraying machine: a horse-drawn wagon mounted with a 150-gallon tank and an eight-foot scaffold. It looked unwieldy, but it was actually the least convoluted rig he could find that would allow him to maneuver his way through the thick woods. Using ladders and the scaffold, the men clambered up the trees, their spray nozzles pointed aloft. From a distance, they looked like humongous long-nosed insects. The spray's pale-blue residue gave the trees a ghostly cast.
Even as he was spraying the trees, Merkel was skeptical that the treatment would work, given how fast this mystery disease was sweeping through the park. He decided to get another opinion and sent word across the road to the New York Botanical Garden's resident expert on fungi, an ambitious young Virginian named William Alphonso Murrill.
Tall and robust, with a fastidiously groomed beard and an affable manner, Murrill, age thirty-four, had only recently begun working at the botanical garden. But he would rise rapidly through the ranks. In just a few years, he would be appointed assistant director, and the garden's staff would become accustomed to seeing his imposing, immaculately dressed figure touring the expansive grounds at least twice a day. Often, he would return at night to make sure all was well.
Murrill came from a long line of Virginia gentry, though by the time he was born in 1869, the family was richer in learning than in money. His parents, former schoolteachers, raised him and his six siblings on a series of farms. He spent a happy childhood roaming the countryside catching frogs and moles and collecting wild pawpaws, walnuts, and chestnuts. He recalled those years in one of his three self-published memoirs, all written—bizarrely—in the third person: "The sights and sounds of the fields and woods made a deep impression on his childish heart and a love for nature was planted deep in his breast." For the rest of Murrill's life, the natural world was a source of wonder and solace; in later years, he would insist that nature study was "the great uplifter of the race." Nothing made him happier than an afternoon spent tramping around the countryside, butterfly net in hand, tin collecting case for plants slung over one broad shoulder and backpack crammed with lunch, specimen bottles, twine, paper, and other gear over the other. He'd gather whatever caught his avidly curious eye: flowers, insects, plants, fossils, rocks, and small animals. He was a born collector whose treasures included butterflies and bibles, stamps and shells. That acquisitive passion drove his professional life: over his career he collected a staggering seventy-five-thousand-plus botanical specimens, including seventeen hundred that were new to science.
Propelled by ambition and a scholarly bent, the young Murrill pursued studies in agriculture, mechanics, literature, and Greek, earning two bachelor's degrees and a master's. At each step of the way he excelled. At the age of twenty-three, he took a job teaching at Wesleyan Female Institute in Staunton, Virginia. He knew, however, that he didn't want to spend his life as a teacher, and in between a busy schedule of classes, hikes, Sunday school lessons, and trips to the nearby University of Virginia to hear lectures, Murrill gave serious thought to his future life work. As he recalled—with a typical lack of modesty— in his autobiography: "With a splendid heritage of health, brains, character and determination, he was anxious to labor in the field best suited to his particular qualifications, thus assuring an easier and more certain success." Eventually, he decided to pursue a career as a scientist, a calling which he thought belonged to those dedicated to "beauty, justice and truth." He initially planned to study zoology, but a friend convinced him there were more job opportunities to be had in botany. He earned a PhD at Cornell University, cultivating a specialty in the study of fungi.
Murrill's wife, Edna Lee Lutrell, whom he'd married while at Cornell, often accompanied him on his mushroom-hunting excursions, painting illustrations of the fungi he collected. But when he began traveling abroad, she refused to follow, for she was deathly afraid of water. Murrill believed that rearing children—ideally, one boy and one girl— was "one of the main objects of matrimony." Yet this was one ideal he could not realize: a son born to the couple died in infancy, and they never had another child. In later years, the marriage deteriorated, and eventually Edna moved out and filed for divorce. It must have remained a bitter memory; when he published his autobiography decades later, at the age of seventy-six, he never mentioned her.
Murrill was a man with many interests: he loved poetry, wrote hun dreds of songs, read Greek and Latin, had a fine singing voice, and could entertain a parlorful of guests on the piano. He was a prolific writer, penning a number of children's books, five hundred scientific articles, and hundreds more for popular magazines. He had been raised in a religious household and as an adult read Bible verses—in different languages—to himself every night. Yet he considered science his true religion. "I am wedded to science," he fervently declared at the age of twenty-six. Unlike his marriage to Edna Lee, this one never faltered. One way or another, almost any issue could be resolved through careful study and the application of scientific principles. Like many of the era, he was a believer in physiognomy and was convinced that the same close observation that yielded so much information about a botanical specimen could be used to reveal human character. The shape of one's figure, the depth of a man's chest, the width of a woman's hips, the coloring of his hair, the flush of her cheeks—all of these characteristics might illuminate an individual's history and character. This led to some strange conclusions, such as his insistence that a snub nose was a sign of ignorance and laziness, while a straight nose indicated "mentality and culture." (His own nose, naturally, was long and straight.)
When it came to the plant world, Murrill held strong and precise convictions. In botanical circles, his interest and skill in discerning subtle differences earned him a reputation as a "splitter," who classified specimens into ever more discrete species and genera. For years he was criticized and attacked by "lumpers," who accepted a higher level of individual variation among organisms than he did. But Murrill refused to budge in his classifications, and decades later, experts conceded that, in many cases, he had been correct.
In his self-published memoirs, Murrill comes across as a strange mix of dreamy romantic and calculating pragmatist. He is also often pompous and didactic. He refers to himself as "The Naturalist" and offers maxims, often clunky, of his own devising, such as, "To be strong and independent, a man doesn't have to drive his lawn-roller over his neighbor's chicken coop." Yet though he seems a blowhard in print, his effect in person must have been different, for he had a reputation as "a charming Southern gentleman" who socialized easily with some of the most powerful and prominent people of his time, from European royalty, to the DuPonts, to the great naturalist John Burroughs.
After graduating from Cornell, Murrill moved to New York City to take another teaching job at DeWitt Clinton High School. But he had his sights set on bigger things. He joined the city's influential Torrey Botanical Club, where he made valuable contacts with leading botanists of the day, including the powerful director of the New York Botanical Garden, Nathaniel Lord Britton. Murrill used his vacations to travel in Europe conducting research for a series of articles that he published in the club's bulletin. His break came in 1904, when the staff mycologist at the botanical garden resigned. Britton tapped Murrill to fill the post. It was the moment Murrill had been waiting for, his chance to prove his mettle as a professional naturalist. Not long after came Merkel's worried message about the zoo's dying chestnuts. It would lead him into the greatest challenge of his career.
Murrill hurried over to take a look at the trees in the park. He agreed with Merkel—this looked like a fungus, but not a Cytospora. So what was it? Murrill cut out specimens of diseased bark from infected trees and then returned to the botanical garden, where he carefully examined the chestnuts there on the grounds. Many of the trees, he found, were under assault by the same unidentified enemy. It had even reached chestnuts in the garden's vaunted hemlock forest, a gorgeous forty-acre wood of virgin timber. In one tree, the deadly parasite had taken root around a heart and set of initials some lovesick lad had carved into the trunk.
The infection was too widespread to conduct reliable experiments outdoors. Instead, Murrill set to work in his lab in the garden's Museum building, starting the steps that German pathologist Robert Koch had established twenty-five years before to isolate and identify a pathogen. He grew specimens of the fungus until he had satisfied himself that he had a pure culture. He then transferred the cultures onto various media—agar, bean stems, and sterilized chestnut twigs—and placed them in glass test tubes sealed with wads of cotton wool. Sure enough, the fungus grew, the fungal filaments fanning out in a pure-white mat of mold that later sprouted a lush bloom of what Murrill described as "beautiful yellow" pustules. Then he infected living chestnut twigs and watched again as the mycelium took hold and blossomed with the same sunshine-colored, spore-producing spots. The next step was seeing if the infection could be induced in living trees, but for that he had to wait out the winter, during which deciduous trees like chestnuts hibernate in a dormant phase. Once spring arrived and the trees' growth systems were back up and running, he inoculated a number of potted young chestnuts in the garden's greenhouses. As expected, he reported, "the actively growing fungus, when transferred from bean stems to the branches of the young trees, attacked them with vigor and soon caused their death."
By spring, he had worked out the essential life cycle of what would come to be known as the chestnut blight. Succeeding generations of scientists equipped with more powerful technology would fill in the details of its precise mechanisms, but Murrill firmly established the basics with his glass test tubes, bell jars, microscope, and careful field observations. He outlined his findings in June 1906 in an article in the Journal of the New York Botanical Garden. He had determined that the fungus works beneath the cortex, the tough outer skin of the tree. It begins when spores gain entry into the vital space between the inner bark and the cambium, the thin layer of life-sustaining cells that carry water and nourishment from the roots to the branch tips of a tree. As the spores germinate, they extend tiny threadlike filaments that eventually weave together to form a mat, the mycelium or body of the fungus. The mycelium pushes, wedgelike, through the living tissue of the tree, and as those inner cells die, the bark above also dies, leaving a sunken, pale-brown depression. Later, fiery-colored fruiting pustules push up through the bark, minuscule volcanoes filled with millions of spores.
Murrill found that this fungus, like many, produces two types of spores. The first type, produced asexually, is extruded in sticky masses of reddish-brown threads that spread through rain or on the feet of insects, birds, and animals. After the fungus has cycled through several asexually produced generations, it starts to generate sexually produced spores, which typically erupt in late summer or early fall in an explosion of powdery yellow specks that are carried far and wide by the wind. When the fungus was most active, usually in the spring, the whole process unfolded with devastating speed. As Murrill reported: "Mycelium inserted beneath the bark of living chestnut twigs on December 13 developed a prominent spore mass by December 27."
The fungus was an efficient executioner. Once it penetrated a point on a tree—a branch, for instance—the mycelium would quickly encircle the limb until the limb was girdled and the food and water supply was completely cut off.* If the attack commenced on the tips of branches, the disease could only progress slowly, since the affected area was small and nourishment scanty. If, on the other hand, it hit at the base of a young tree where it could tap into a treasure trove of moisture and food, the fungus grew fast and the tree's life was quickly in danger. The fungus could kill a mature tree in just two to three years.
"There is no mistaking the blight when it appears," Murrill reported. First, a flush of orange-red spots would appear on the bark and the area beneath would sound hollow if tapped. If the tree was young, a round, sunken, discolored patch on the bark would appear, with cracks running up and down. Infected sprouts would swell at the base and could be easily snapped off. Finally, the leaves would turn a distinctive dark brown, "as though scorched by fire."
As much as Murrill had learned about the new disease, there were still many unanswered questions. For instance, he wasn't sure how the fungus gained entry to a tree in the first place. His experiments suggested it wasn't able to muscle its way through the outer skin unless
*In fact, the tree's own defensive effort to seal off the invading mycelium also blocks the transport of water and nutrients, ultimately leading to its death. In essence, the tree commits suicide.
there was some break in the bark, however tiny. He presumed infection took place through wounds, be they caused by weather, the scramble of squirrels, the nesting of birds, the chewing of insects, the lumberman's axe, or what he called "the savage hordes of small boys" who every fall pelted the trees with sticks and stones to dislodge the nuts. Then, too, he suggested, the chestnut's legendary powers of regeneration might make it more vulnerable to this new scourge. Most of the chestnuts in the region were incarnations of previous chestnuts, sprouted from the original stumps. Such repeated resprouting, he suggested, sapped a tree's strength, undermining its ability to fight off infections.
Nor did he know the identity of this new lethal predator. Murrill searched the reference books and consulted other mycologists, but as far as he could tell, the disease had never before been described. He finally decided it was a new rogue member of a large genus of fungi known as Diaporthe. Members of the clan generally do not prey on living tissue; their appetites are limited to dead wood. This pest, on the other hand, was definitely a parasite with far more destructive habits, a point he tried to underscore in the name he chose for it: Diaporthe parasitica Murrill. (The classification would prove controversial; within just a few years tax-onomists would reassign the wily fungus to a different genus of molds, Endothia. It would be reassigned yet one more time in 1978, when scientists decided that its true lineage was with the genus Cryphonectria. Today it is known as Cryphonectria parasitica.) Murrill had no clue where the fungus originated. He suspected—wrongly as it turned out— that it was native to the East Coast and that it was the product of a slow and quiet mutation in the normally harmless Diaporthe.
Because the disease did its dirty work under the bark, Murrill was dubious that any amount of spraying of the tree's surface, even with as strong a brew as Bordeaux mixture, could have an effect. Still, he tried to be hopeful, suggesting that older trees might be rescued by cutting out the affected areas, burning the cut limbs, and dressing the wounds with creosote or tar. He thought young trees had more of a Wghting chance and that "vigilance and care should largely control the disease"
among them. But even as he was writing the words, it was becoming clear those hopes were in vain.
Like many New Yorkers eager to escape the suffocating heat, Mur-rill left town for the summer of 1906. On his return in August, he was shocked by how rapidly the plague had spread, fueled by weeks of warm, moist weather. "I now know of very few chestnuts in this portion of the city that appear to be worth trying to save and I do not consider any immune," he reported in the Journal of the New York Botanical Garden that September. "The natural result must be the death of practically all the chestnut trees in the infected area, unless some exceedingly active enemy speedily appears; which is extremely unlikely." The disease was not only ravaging all the parks in the Bronx, but it had leapfrogged south across the thirteen-mile-long island of Manhattan to infect chestnuts in the green swards of Brooklyn. Even more worrisome were unconfirmed reports that the disease was present in New Jersey and as far south as Maryland and Virginia. This was clearly an epidemic, and as with all epidemics, Murrill believed, there seemed little to do except let it run its course.
Even as Murrill was sounding the alarm, he failed to grasp the magnitude of the threat. He still assumed that the epidemic would burn itself out and that the dead and dying trees could then be cleared away so that new chestnuts could be planted to take their place. The word blight, with its implications of pestilence and permanence, had not yet entered his vocabulary. He called the disease the "chestnut canker" for the lesions it produced, but the phrase also suggested something that might eventually be managed. This disease would not be contained or controlled, however; the very existence of the American chestnut was in peril.
"Chestnut Trees Face Destruction," the New York Times headline announced on May 21, 1908. Four years after Merkel's discovery, the epidemic had become so widespread that even the most casual gardener could not help but be aware of it. "The wail of the chestnut lover is heard from all parts of New York, Long Island and adjacent country," the Times reported. Dying chestnuts were now major news, though not quite important enough to join such stories on the front page as the new speed record set by the steamship Lusitania, the story of a woman who developed an unseemly "mania" for football, or the first birth of a Rocky Mountain goat at the zoo in the Bronx.
Chestnuts may not have been as significant for city dwellers as they were for residents of rural Appalachia, but they were nevertheless cherished trees. "The chestnut trees are our special friends of the forest," one fan wrote in American Forestry in 1912, "and around them are particularly pleasant memories of the time, when in our youth, we gathered their fruit." Nutting parties were an annual autumn ritual in the cities and budding suburbs throughout the chestnut belt. "Not only country boys—all New York goes a-nutting," Henry David Thoreau observed. People flocked to chestnut groves in the great parks of the Bronx—van Cortlandt Park, Crotona Park, Bronx Park—or rode the train just a little bit farther north to the wooded outreaches of Westchester County. Once they might have hunted squirrel or rabbit in those hills, but by the turn of the century, the main quarry left was chestnuts.
Dried brown leaves would cling to the woolen hems of women's long skirts as they looped ropes around the branches of chestnut trees and yanked hard to shake the nuts free. Waiting children scrambled on their knees to gather them up. If a tree's branches hung low enough, adventurous boys or men clambered up to stand on the limbs and stamp a few times to rattle the nuts loose. (Females were strictly discouraged from this mode of chestnut-hunting.) It could be a perilous venture: every season brought reports of casualties, like the New York lawyer who died of a broken back after falling twenty feet while trying to shake some nuts down for his children.
In the outskirts of Philadelphia, the writer Clarence Weygandt reported, boys prowled the thick stands of chestnut armed with the requisite weapons for the hunt: clubs fashioned from broomsticks or hickory wheel spokes that were weighted at one end with metal clock weights, pieces of lead piping, or best still, the iron nuts used to fasten railroad tracks in place. So many iron nuts were stripped off one suburban Philadelphia railroad line that the track walker took to carrying an extra supply of nuts during chestnut season. Weygandt wrote appreciatively of the pleasures of chestnut clubbing: "It requires strength and dexterity and long practice to send even a skillfully weighted club to the top of an eighty-foot tree. . . . Who is there who does not recall the joy of a strike. Talk of a three pound trout or a six pound bass in the same breath with this rapture!" Young boys were not the only ones drawn to the woods in the dim October dawn; Weygandt regularly spotted grown men "in whom the country heart is still alive" scouring the area for nuts.
Other nuts could be found in the woods on a crisp fall day. There were walnuts, butternuts, beechnuts, and hickory nuts, too. But the chestnut seemed to spark a special devotion. Was it the beauty of the nuts, shiny and smooth as polished rosewood? Their sweet, delicate flavor, which could be savored raw, as well as boiled or roasted? The casual prodigiousness with which the trees carpeted the ground with their seeds? "The very fact that we have, besides the general term nutting, only the one specific term chestnutting, tells the story," Weygandt wrote. "Who has heard of walnutting, or butternutting or shellbarking?"
Perhaps the love of chestnutting stemmed in part from the pleasure of foraging, that most ancient mode of sustenance. "I love to gather them," Thoreau wrote, "if only for the sense of the bountifulness of Nature they give me." That awareness, honed through foraging, was hardly necessary to survival in a city. Yet chestnutting helped sustain a connection to the natural world that was fast disappearing under ribbons of asphalt and walls of concrete.
Now New Yorkers were facing a disease that threatened to eradicate every last one of their chestnut trees. The blight had accelerated rapidly in just a few years. In Brooklyn's Prospect Park, alone, fourteen hundred trees had died by the summer of 1908. At the New York Botanical Garden, workers had cut down at least three hundred dead or dying chestnuts, including grand old giants as wide across as a man is tall. Murrill had watched helplessly as dozens of chestnuts around his home in nearby Bronxwood Park died. All told, he estimated, five to ten million dollars' worth of chestnut trees had been lost in the greater New York area. And the outbreak had continued to broaden, threatening pandemic proportions: there were now reports of the disease in Connecticut, Massachusetts, and Washington, D.C. Appalachia was still blissfully ignorant of the spreading plague. The chestnut trade in places like Patrick County, Virginia, was still booming—though not for long.
With his new job as the assistant director of the botanical garden, Murrill's duties had grown. An engaging speaker, he was becoming a Wxture on the garden club lecture circuit. He continued to expand the garden's collection of fungi and was getting ready to launch a new journal devoted to mushrooms called Mycologia. Still, the chestnut disease was consuming a good part of his time. In ongoing experiments, he was learning new and unsettling things about this pathogen. He found the fungus had unparalleled strength: when other fungi had accidentally gotten into cultures of blight fungus, the blight mycelium rolled right over them, diminishing Murrill's hopes that the disease might be brought to a halt by some equally powerful pathogen.
More disturbing, though, was his discovery that the fungus did not conWne its predations to the American chestnut. It also attacked at least three other species of Castanea. He'd found it on native chinquapins in the botanical garden, as well as on one of the garden's Japanese chestnut trees. When he inoculated a number of those trees with the fungus, all had succumbed, though later it would become clear that the Japanese trees were generally resistant to the fungus. Worst of all, a Long Island man with an estate full of European chestnuts had informed him that those trees were also susceptible. That last revelation was deeply alarming, for Murrill knew how valuable chestnuts were in Europe, especially in the mountains of Italy, where the nuts were a staple of the diet. He took it upon himself to notify the Italian consulate in New York of this concern and spent a day sharing his data with a member of the Italian legation. "He was a man who had been in the chestnut business," Murrill told the Times, "so he recognized at once what the spread of the disease would mean to the people there." Murrill began urging the U.S. government to act to prevent the disease from being introduced to Europe or to other parts of the country. "There should be a law to prevent the shipping of our chestnut trees to other states," he insisted, on learning that some trees were recently shipped to California. Though Canada would soon pass an import quarantine, the U.S government was slow to heed his call.
As the leading expert on the new disease, Murrill enjoyed the spotlight, but he grew weary with the more tedious aspects of that position. There seemed to be a never-ending stream of what he termed "piteous pleas" from homeowners anxious to save their beloved trees. Each tree was worth about one hundred dollars, and Murrill knew a well-placed mature tree could add as much as a thousand dollars to a property's value. Unfortunately, he had little advice to offer aside from four succinct words: cut the trees down. The city's rich and famous beseeched him for help, yet not even Teddy Roosevelt or John D. Rockefeller could do anything to save the chestnuts on their estates. Murrill had little patience for pseudoscience, and now he fumed over the multitudes of quacks traveling the countryside trying to cash in on people's desperation with bogus remedies. It was said a tree could be saved by pouring poisonous solutions on the roots or filling in holes with sulphur. Murrill scoffed at the suggestion: "It would do as much good to fill the hole with gravel as to use sulphur in that way," he told the Times.
He was equally irritated by the continuing barrage of speculations about the causes of the disease. There was no shortage of theories, scientific and otherwise. Murrill got letters from people who saw the blight in apocalyptic terms, blaming "sinfulness and extravagance [and] the general wickedness of the people of the United States" and suggesting that "perhaps prayer or a grand religious revival might stay it."
One scientist attributed the outbreak to the demise of woodpeckers that might have killed off spore-carrying bugs. Another suggested the disease highlighted the dangers of permitting people to hunt native birds: "It is very likely that some of the birds that have been reduced almost to extinction had the all important duty of keeping this particular enemy of the chestnut in subjection... . Now we pay for our carelessness by losing the trees." Amateur entomologists linked it with a variety of unnamed bugs. One man described a tiny black insect he'd seen on his trees before they succumbed to blight. A Philadelphia florist insisted that it was caused by a small black beetle that looked like a ladybug. That was "simply out of the question," Murrill snapped in response, clearly annoyed that years into the epidemic he was still having to defend his most basic findings. "The chestnut canker is caused by a definite parasitic fungus. ... There is absolutely no doubt about it."
But perhaps most frustrating of all was the official response of the USDA. The agency had finally become interested in the chestnut problem, but as Murrill saw it, the government scientists were feeding false hopes. In 1907 the agency established a Laboratory of Forest Pathology to deal with the growing roll call of tree diseases: peckiness, pine rot, ink disease, plum black knot, and of course, chestnut blight. Forest pathology itself was a relatively new discipline, a latecomer to a science that traditionally had been concentrated on diseases affecting food crops and orchard trees. That focus began to change at the turn of the century with the rise of the conservation movement and growing interest in the nation's forests as a splendid but endangered resource to be enjoyed and exploited. In 1905 the U.S. Forest Service was established with the goal of preserving timberlands for continued use through scientific management. Suddenly, there was an interest in promoting healthy forests. As Secretary of Agriculture James Wilson declared, "the rapidly growing interest in forestry problems has created a widespread demand for information as to diseases affecting trees."
Chestnut disease was certainly not the only problem on the new pathology lab's agenda. The lab had its hands full battling what the New York Times called an "appallingly vast army of parasites." The incomparably valuable white pines of the Northeast were under attack by a new lethal pathogen that sapped the life from their sprays of delicate green needles, turning them a scorched-looking, rusty brown. The graceful vase-shaped elms were being stripped of their leaves by a vicious beetle that had entered the United States from Europe. That tough forest stalwart, the hickory, was under siege from another bark beetle. But destructive as each problem was, none compared to that of the chestnut blight. "It is no exaggeration to say that it is at present the most threatening forest-tree disease in America," wrote Haven Metcalf, the first chief of the Forest Pathology Lab and another young up-and-comer.
Metcalf was a thick-cheeked New Englander with a prominent bulbous nose and round tortoiseshell glasses. Raised in rural Maine, he got his undergraduate degree at Colby College and then left his home state to pursue graduate degrees, hopscotching among various of the leading universities of the day to study botany, bacteriology, and mycology. He earned a PhD at the University of Nebraska, where he studied with Charles Bessey, one of the pioneers of American plant pathology. (Bessey had been among the first botanists to advocate the use of laboratory techniques and equipment; in 1873 he startled colleagues at Harvard by outfitting his office with a microscope, jars of preserved material, reagents, scalpels, needles, razors, and other equipment and hanging a hand-lettered sign on the door that read "Botanical Labora tory." Soon lab work was a requirement for botany students.) After a brief series of teaching stints, Metcalf joined the USDA's Bureau of Plant Industry in 1904. Though his prior experience was in agricultural diseases, in 1907, at the age of thirty-two, he was picked to head up the newly created Forest Pathology Lab. He quickly surrounded himself with a staff of impeccably credentialed young scientists and set them to work on the chestnut crisis.
Unlike Murrill, Metcalf was not yet persuaded that the chestnuts were beyond salvation. He insisted that individual trees might be saved by cutting off the affected branches and spraying them. Murrill disputed the suggestion, noting such methods had been tried and failed. Treating a large tree would cost at least a hundred dollars, "and it's a waste of money," he bluntly told the New York Times. "A tree sometimes takes the disease in twenty places at once, and they may be in the highest branches of the tree where a squirrel could barely reach them." After grappling with this chestnut killer for several years, Murrill had become Wrmly convinced that "there are absolutely no remedies against it, in spite of what Secretary Metcalf says."
For a man who waxed rhapsodically about the transcendent glories of nature and who wrote that the trees one knows "will never be forgotten, but will be recognized and loved as the faces of one's friends," Murrill was remarkably unsentimental about the plight of the chestnut. His autobiography suggests that he coolly regarded the chestnut's bad luck as his good fortune: "The chestnut canker was just another timely round in the ladder of luck he was climbing to fame and influence. When the opportunity appeared he was ready."
Perhaps Murrill remained unaffected because he was at heart a collector, a taxonomist, driven by a passion for identifying and classifying new species. Once he'd catalogued the chestnut's foe, stamped his name on its identity, and established its workings, his interest in the fungus seemed to wane. Then, too, Murrill was a scientist first and foremost, clear-eyed and strictly tethered to the facts on the ground. And the facts, as he now saw them, left no room for hope. "If this disease continues as it has begun, there is, theoretically, no reason apparent why it should not sweep from the country practically every tree, both native and cultivated, of the genus Castanea," he told members of the Torrey Botanical Club in 1908. If he felt grief or pain over the potential loss of this particular friend, he never expressed it. When a reporter asked him about the decimation of favorite shade trees like elms and maples by various pests, he replied that the solution was to simply stop planting such vulnerable trees. "Certain trees, like the chestnut—which is doomed—the sugar maple and the elm are too sensitive to ordinary cultivation, especially in cities." Better to plant hardier varieties like oak or sycamore, he advised. "Otherwise, it is tempting fate."
But Metcalf and others were not yet willing to consign the chestnuts to fate. Though Metcalf eventually came to agree with Murrill that individual trees were beyond rescue, he was still hopeful that the epidemic could be staunched before it reached the valuable chestnut stands of Appalachia. He, like other federal scientists, thought the answer was a quarantine. The use of quarantines had helped wrestle such agricultural pests as pear blight and peach yellows to the ground, as well as human scourges from the Black Death to yellow fever. As then— Secretary of Agriculture James Wilson observed, "There is no contagious disease known that does not yield to sanitation and quarantine." In the fall of 1908, Metcalf decided to test the efficacy of quarantine in the area around Washington, D.C. Scouts from his lab scoured the woods within a thirty-five-mile radius for signs of infected trees. They found 1,014 "points of infection," ranging from a group of nursery trees imported from New Jersey to a single lesion on a wild chestnut in a forest. Every affected tree was cut down and destroyed, and Metcalf directed that the site be monitored for the next several years.
Metcalf knew what was riding on the outcome of the experiment. Failure ensured the loss of one of the country's most important trees, a resource worth at least three to four hundred million dollars, or about nine billion dollars in today's currency. "The stake for which we are fighting is nothing less than the present stand of chestnut timber in America," he told a reporter. "Unless the disease is controlled by human agency or unless some natural enemy appears to check the disease— and there is no hope of this—the chestnut tree will become extinct within the next ten or fifteen years."
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