Season to Taste (13 page)

He forgot about her until that evening—an evening he would later dub the
Night of the Great Peacock
. Around 9:00
P.M.
, as he and his family began to get ready for bed, Fabre heard the yells of his son, Paul. “Come and see these butterflies!” Paul shrieked. “Big as birds! The room’s full of them!”

As Fabre ran toward his study with his son, he was greeted with a cloud of moths. Giant ones. Peacocks, just like the one which had metamorphosized that morning in his lab. They had invaded the house and fluttered around to the delight of both the scientist and his small child.

“Candle in hand, we entered the room,” Fabre wrote in
Social Life in the Insect World
. “What we saw was unforgettable.” The study was full of moths, arriving mysteriously at his home as night fell. They surrounded the female’s cage. “They rushed at the candle and extinguished it with a flap of the wing; they fluttered on our shoulders, clung to our clothing, grazed our faces. My study had become a cave of a necromancer, the darkness alive with creatures of the night! Little Paul, to reassure himself, held my hand much tighter than usual.”

Fabre kept his original winged female moth in the following days and kept many more moths in the following years. He watched as clouds of males arrived—together and silently—night after night. They stormed the study like a horde of princes at Rapunzel’s castle, coming from miles away. They were there to mate, this much Fabre knew. But he wondered how these creatures knew where to go. There were no maps, no sounds or smells noticeable to anyone else. “What sense is it that informs this great butterfly of the whereabouts of his mate, and leads him wandering through the night?” he wrote.

Fabre tested many of his theories on the moths. Their signal, he thought, must be airborne because females still attracted mates when held in a porous but opaque container, though not when the air around them was completely sealed. He tried removing the males’ antennae, but lacked conclusive results, and then tried drowning his study in the powerful stench of naphthalene, spike-lavender, petroleum, and a solution of alkaline sulfur—an odor mixed of rotten eggs, mothballs, and gas. But not even that masked the power of the female’s signal. He played with the idea of electric or magnetic waves, “like a system of wireless telegraphy”—“I see nothing impossible in this; insects are responsible for many inventions equally marvelous,” Fabre wrote—but in the end, he decided, the female must attract the men with a scent. Not an ordinary scent, however.

“I was now convinced,” he wrote. “To call the moths of the countryside to the wedding-feast, to warn them at a distance and to guide them the nubile female emits an odour of extreme subtlety, imperceptible to our own olfactory sense-organs. Even with their noses touching the moth, none of my household has been able to perceive the faintest odour; not even the youngest, whose sensibility is as yet unvitiated.”

The moth’s mating habits had everything to do with smell, he believed. He wasn’t quite right. But he was close.

Fabre’s observations became what was the first step in the still-going study of invisible chemicals—chemicals that bounce among members of many species and affect behaviors of all kinds, that allow an ewe to recognize her newborn, an ant to signal danger to its colony, and those male moths to be summoned to mate. Today, these chemical interactions are some of the most important ways of understanding how animals interact.

Pheromones.

It took almost half a century to come up with the word. That didn’t happen until 1959, when a German scientist named Adolf Butenandt, who had already won a Nobel Prize in Chemistry for his work in sex hormones, discovered the first chemical composition of a pheromone. Butenandt had spent many years painstakingly testing the silk moth
Bombyx mori
. He went through more than half a million moths, trying to isolate the sex pheromone. Fabre had wondered for years how that feathery-winged creature could so silently summon her lovers from miles away. What kind of signal has that power? Butenandt found out. He isolated the specific chemical released by the female moth to attract the mating males. He called it
bombykol
.

But the actual term “pheromone” was coined by two others: German scientists Peter Karlson and Martin Lüscher. They came up with the word in 1959, timed with the release of Butenandt’s paper. They knew that the behaviors influenced by chemicals would go far beyond those of the silk moth and, therefore, that the phenomenon needed its own word. Karlson and Lüscher combined the term from the Greek
pherein,
to transfer, with
hormon,
to excite.
To transfer excitement
: it stuck.

Pheromones, they wrote in their 1959 article entitled “ ‘Pheromones’: A New Term for a Class of Biologically Active Substances,” are “substances which are secreted to the outside by an individual and received by a second individual of the same species, in which they release a specific reaction, for example, a definite behaviour or a developmental process.” The scope of their definition is wide. And perhaps rightly so: pheromones have been found in algae and elephants, goldfish and lobsters. There are pheromones that signal fear and aggression. There are pheromones that elicit sex and those that signal kin and territory. There are pheromones that influence puberty and hormones and emotion. They dictate much in the life of animals. They skirt the line of smell and intuition, mystery and science, evolution and common sense. Invisible and potent, these naturally secreted chemicals function as a language of their own, silently curling their way around primal and sustaining acts of life.

The paths of these chemicals can be complex. Most animals react to a very specific ratio and combination. Many are still unknown. Today, the chemical composition of what, exactly, drives a male dog toward a female in heat remains elusive. But in 1996, for example, it was discovered that the female Asian elephant, that wrinkled mammoth who lives in small matriarchal groups, has the same sex pheromones—the one called “(Z)–7–dodecen–l–yl acetate”—as various species of insects, simply used in different ways.

Detection varies widely. Animal pheromones can be found in urine—think of a dog who sniffs or marks a tree—or are wind-borne, like the pheromones of the moth. Fish pick up water-soluble chemicals as they swim. Male Queen butterflies deposit their pheromones right onto the antennae of their female companion. Male terrestrial salamanders drop theirs straight from their chin into the female’s nostril.

But how do animals process pheromones? Does it happen in the nose? Is it as simple as a sniff?

The
vomeronasal organ
(VNO) is a tubular duct running separate from the olfactory system that plays an important role in the process for many species of animals. It was discovered by a scientist named Ludwig Jacobson in 1811. It’s a sneaky little thing, like a second nose but not part of the nasal cavity. It’s a cavernous, winding path filled with protein receptors primed to pick up chemicals and send their signals to the accessory olfactory bulb and, later, to the higher echelons of the brain.

In the past, scientists have believed that this pathway was the only place possible to process pheromones. They believed that it was the source of mystery, that it was the entryway to chemical communication. It’s been found, however, that the traditional olfaction pathway—the basic sense of smell—is important as well. For example, in 1997 scientist Kathleen M. Dorries blocked the vomeronasal organs in domestic pigs with surgical cement. She and her colleagues then tested the reaction of the female to their sex pheromone,
androstenone
. They found that both the pigs with blocked VNOs and those with clear reacted the same way: excited, ready. The vomeronasal organ, Dorries concluded, wasn’t completely necessary. It wasn’t the sole pathway of chemical communication.

The animal brain, then, takes cues from both the VNO and the central olfactory system. Animals’ worlds are defined by the nose and the brain, the chemicals and the aromas.

In those first months that I lived in New York I didn’t know about those silk moths, who found their mates with little more than a puff of chemical. I didn’t know about those pigs on a farm upstate, who snorted around the androstenone and were immediately ready for love. If I had, I probably would have been jealous. Those animals didn’t have to worry about the scent of Old Spice, or a rank twang to a lover’s BO. For humans, however, the concept of pheromones is both elusive and controversial.

ON AN AFTERNOON
late in April, when the harsh winter chill had begun to lift, I met a man. We’ll call him David. Short and stocky with wild curly hair, David had lived in my apartment the year before I moved in. He was a writer working on a book, now living in a one-bedroom apartment a few blocks away. On this day, he wore a bronzy linen shirt and gray pants. He had stopped by to pick up some of his old things that had been left in our hallway storage space.

When I answered the knock at the door, he smiled and shook my hand. His fingers felt warm; his palm, thick.

I leaned against the wall as he packed up nearby, chatting casually while he organized the muddle of artifacts stacked in the hallway, the ones that had been there for years now, he told me with a guilty shrug. There were boxes of books and plastic containers of clothes. There was a thick brown mask made of pottery and straw, which reminded me of the goods sold in the markets of Namibia I had seen years before. I asked him about it, and he told me stories of his travels and his years in the Peace Corps. He segued into stories of his work as a journalist and I listened hungrily, both intimidated and enthralled. He asked me what I did and I swallowed, embarrassed, before admitting my struggles to find a job. I had just begun an unpaid internship at an art magazine, where I sat obediently opening stacks of mail in an office without windows. I felt young at work. I felt young at home. I was surprised to find myself telling David that I wasn’t sure if I would ever find a career that I could like, certainly not a job that didn’t involve the kitchen, that had nothing to do with food. He looked at me warmly, though, and smiled. He told me that I would be okay.

A week later we sat across from each other at a table in the dark corner of a bar nearby. His fingers rested lightly on the base of his wineglass as smoke from cigarettes curled up in the air nearby. Again, we talked about writing and travel. We talked about work. All the while I stared at his eyes, which were dark and a little bit strange. They were crooked, I realized. The right eye was level but the left tipped in a lazy slope downward—an asymmetry hinting of vulnerability, a body not quite put together correctly. In the past, I had fallen for athletic men who reeked of confidence. David was different, but I couldn’t look away. His vulnerabilities reminded me of my own.

He kissed me on the stoop of my apartment, in the dark drizzle of a rainy Sunday night in June. He held my face with his hands. I couldn’t smell his breath; I couldn’t smell skin. But I felt something, then. I felt a lot.

AS AN UNDERGRADUATE
at Wellesley College in the late 1960s, Martha McClintock lived in a dorm filled with dresses, long hair, and breasts. Among the women there, she noticed something interesting—more interesting than the catfights or makeup tips commonly associated with large groups of girls. She noticed that, over time, her dorm mates’ menstrual cycles synchronized.
Why?
she asked.

McClintock, who is today a professor at the University of Chicago and founder of the Institute for Mind and Biology, published a paper soon after graduation about this phenomenon. This mysterious menstrual overlapping among friends and housemates, she determined, was due to unconscious chemical communication. Human pheromones.

As her dorm mates interacted closely and regularly, information was relayed on a molecular level. Tiny blips of information, but over time this information grew to affect life under the skin. The women’s reproductive systems aligned. The McClintock syndrome, as this synchronicity became known, was purported to be caused by the same type of chemical reaction known to happen in animals: silent, undetectable communication between members of the same species in a way that influenced behavior. But what chemical actually caused the women to synchronize? How did it work? Does it come through smell? Taste? Touch?

A generation later, many of these questions are still yet to be answered. They are stymied in part by a lack of funds. They are slowed by the sheer numerical density of the molecules released from human skin—a number, I’ve been told, that would take untold years to isolate and identify their singular effects as Butenandt did for the moth. (Can you imagine so many molecules constantly flying away from your own body, whispering secrets to your companions without your knowledge?) These questions are also plagued by doubt: the study of human pheromones has been viewed with apprehension for decades.

McClintock’s first paper fueled enthusiasm for research on this mysterious, elusive topic. She has been joined by many others. It is still going strong.

In 1998, McClintock published another paper on pheromones and menstruation, this time with scientist Kathleen Stern. In this study, they had a group of women apply samples of odorless compounds from the armpits of other females above their lips, where they would breathe it in without thinking. Some smelled samples swabbed from the armpits of women who were currently in the beginning of their menstrual cycle. These smellers experienced a surge of hormones, the scientists found, and a shortened cycle of their own. Other participants smelled samples from the armpits of women who were much later in their cycle—at ovulation. This had the opposite effect: the smeller’s hormone surge was delayed. Her cycle lengthened. “By showing in a fully controlled experiment that the timing of ovulation can be manipulated, this study provides definitive evidence of human pheromones,” the scientists wrote. I read this study, shocked to think that the scent of another woman, then, could change my internal clock and my capacity to reproduce. Or could it? Without a sense of smell, came that anxious little whisper, would I no longer react to the women in my life? To the men?