This essay first appeared in Still: The Journal
by Rachel Rosolina
Into the cage of
fireflies, mostly dead,
I send a breath.
In the early summer twilight, my brother’s tiny silhouette stumbled through the tall grass. He paused, crouching down. In a flash of arm, he reached into the grass and, before standing, opened his fist ever so slightly. I could see his small palm glow yellow green. Samuel had caught a firefly.
They rose like embers from grass up to the wide, pale leaves of the tulip poplars at the edge of the woods. We silently followed their dotted paths, watching their ascent. In an attempt to prolong the magic of dusk, we gently placed a few captives in a mason jar with a tin lid that Mom poked holes in for air. I also slipped in a few blades of grass to make the jar seem less confining. When it became too dark to see the outline of the house, we had nearly twenty fireflies pulsing behind glass. Covered in grass stains and sweat, we walked up the hill, onto the porch, and into the florescent kitchen.
Clean from baths, Samuel and I watched the jar from our bunk beds. All was still except for their ethereal flashes casting shadows about the room. Good night, Rachel. His voice was quiet, calm. And then came the deep sound of his breathing.
My brother is four years younger than me. On the night he was born, according to my father, I was a brat. I threw temper tantrums all evening. The next morning, however, everything was new. There is a photo of me in footie pajamas, with sleep in my eyes and tangled hair, holding this tiny red person—my brother. My eyes look at the camera with wonder and confusion. Even at four, I knew his arrival redefined my place in the world with a new title: sister.
Samuel balances my darkness with his light. Physically, we are opposites—I am olive skinned with dark features while he is fair with striking blue eyes—but it goes beyond the surface. While I dwell and contemplate, he optimistically acts. While I linger anxiously outside, my brother is in the center, making people laugh. His goodness and levity are effortless. For this I both admire and envy him.
We were homeschooled in the mountains of East Tennessee for the majority of our education. Our days were spent side by side doing schoolwork at the kitchen table, swinging on grapevines until our hands were raw, designing tree houses, and imagining kingdoms of periwinkle snails on the little silt island in our creek. We didn’t always get along, but we grew together in ways many siblings don’t have the chance to. Our quiet existence was enchanting and thrilling. Really, we knew nothing different.
The primary purpose of the fireflies’ light, of course, is mating. Most female species of fireflies are wingless, grounded. At dusk, male fireflies flash sequences of light to attract a flightless lover, hoping a female responds from the grass with flashes of her own.
Each summer, the Johnson City fire department sponsored a firefly catch. For every ounce of fireflies caught and frozen, we would receive a few dollars. The beetles would then be used in cancer research. According to the pamphlet, a compound created from the firefly is inserted into cancer cells. Once the reaction begins, the cancer cells glow much like the firefly once did. When a photosensitizing agent is added, the cells produce so much light they die.
Samuel and I spent nearly every summer evening following these flashes in the space between forest and field, grass and sky, carefully slipping them into glass jars, and then watching them until sleep came—only to reluctantly place the beetles in the freezer the next morning.
Samuel lives in Knoxville, where he is pursuing a doctorate in environmental chemistry at the University of Tennessee. A few summers ago, I left my apartment in Indiana to spend a weekend with him. While wandering in and out of quaint indie shops, we ran into friends of his, mostly girls, all excited to see him. During introductions, they would visibly relax when they realized I was merely his sister.
Before Erin—his wife—came along, I never really liked the girls Samuel dated. I scrutinized them: one was too ditzy, another too demanding, yet another too judgmental. With Erin, it’s different. When his car broke down on the side of the interstate after they had just started dating, she was the one he called to rescue him. She knows he’s exceptional but does not put up with his bad habits, such as failing to plan ahead or using humor to get out of trouble. She makes him laugh and takes him seriously.
When he was twelve, Samuel was accepted to sing in a national honor’s choir in Seattle, Washington. While I took tours of the city with the choir mothers, the choir spent the days practicing. We hardly saw the kids the entire trip. The final night, after the concert, we all went to a closing reception. The hotel ballroom had tables of hors d’oeuvres and fountains of punch. From a doorway, I watched my brother interact with his new friends. More and more people surrounded him, laughing when he laughed, smiling when he smiled, wanting a taste of that electricity.
I was overcome with a mixture of pride and jealousy at his radiance. There was the certainty that no matter how many important people came into his life, I was his only sibling—I had been there from the start. And yet, there was an edge I couldn’t ignore. Unlike me, he didn’t have to vie for this attention. I was content being the wallflower only because stepping into the center, as he did naturally, threatened the possibility of rejection. He didn’t seem to even acknowledge that fear.
I used to joke that we couldn’t be more different—he pursuing science and math while I went the English/humanities route. As we get older, though, I’m realizing there are more similarities than I had thought. Science to him is deeper than the black and white formulas I’d imagined. He sees a calculated art in chemistry. His passion for understanding the intricacies of nature is apparent when he talks about his latest research or an article he read. To fulfill an assignment for an organic chemistry course at Berea College, he and his girlfriend at the time decided to study the firefly. Specifically, what makes them glow. During a rare late-afternoon phone call, his voice animated in excitement, he explained that luciferin is the cause. Luciferin as in Lucifer?, I asked. Yes, as in fallen light, he said. Isn’t it poetic?
Many organisms—bacteria, certain fish, and even other insects—use bioluminescence. Nonscientists often confuse bioluminescence with fluorescence, but they are different processes. While fluorescence occurs when energy is absorbed and emitted as light, bioluminescence produces light with what is known as excitation energy from a chemical reaction. For this reaction to occur in fireflies, two reactants—the chemical luciferin and the enzyme luciferase—are needed in addition to a firefly’s ATP, which is a chemical compound that helps cells store energy. Essentially, the luciferin, after combining with the ATP, is oxidized to form oxyluciferin. The luciferase speeds up the reaction.
Firefly luciferase is stored in the abdomen of the insect and has a very specific structure and conformation. The enzyme is built efficiently, which is why the reaction gives the highest known yield of light of any bioluminescent reaction. Take an incandescent light bulb, for instance; it loses 90 percent of its energy to heat. In comparison, the oxidation of luciferin by luciferase converts nearly all of the energy to light. Because this reaction produces little to no heat, only light, scientists refer to it as “cold light.” The word cold makes the reaction sound distant or sterile, but instead it strikes me as sacred and extraordinary. What scientists strive for in labs—little wasted energy—fireflies create organically.
When Samuel and I are together, we play off each other’s sense of humor or read each other’s worries in ways no one else can. We have inside jokes spanning decades, and he knows the quickest way to make me angry. When I look in his eyes, I see who I was and who I am. No matter how old Samuel gets, I will always see the stick of a boy who caught fireflies and built forts by the creek. We will always be the children who, in the dappled light of the rhododendron patch, sat on damp logs to color paper flags, choose crests, and read the official oath to one another in hushed voices—our hands on our hearts. In dull lead, we signed our names in cursive on a clean sheet of lined notebook paper, pledging our allegiance to one another.
When I was eight or nine, and Samuel was about four, he and I spent an afternoon playing with a plastic inflated ball. At some point, one of us kicked the ball onto a rock or stick, puncturing it. Samuel saw my disappointment and anger, and instead of trying to soothe me, he lightened the situation with humor. While I pouted, my little brother quietly took the deflated ball and folded it inside itself to create a domed hat. He playfully put it on and did his best to make me forget and laugh. He knows how to fix me.
We may no longer belong to our secret society, but our pledges endure.
The cold light of fireflies is waning. Fireflies are disappearing all over the United States. Though scientists are not sure why this is happening, they have two good guesses: development and light pollution. As we light up our world, the darkness that helps the fireflies communicate and proliferate has become scarce. Our reaction is to recreate their glow by stringing strands of blinking white Christmas lights across our porches. The reality is that we’re stifling the natural magic and mystery that surround us.
In a remote part of the Great Smoky Mountains National Park, and in a few other parts of the world, synchronous fireflies have become a phenomenon that draws crowds. Though they are one of nearly twenty species of firefly in the park, they are the only species in all of the United States that can coordinate their flashing light pattern. For just two weeks each summer, the males put on a show, lighting up all at once or sending a wave of light rippling through the trees. No one is sure how they communicate to create such an effect. Scientists have speculated that perhaps it is a result of competition, of wanting to be first. Or maybe by working together they have a better chance of being noticed.
Having heard about this spectacle since we were kids, Samuel and I have always talked about witnessing it for ourselves, but life tends to get in the way. This past year, though, Samuel drove Erin down to watch. They parked his old Honda hatchback on the side of the road and made friends with those parked nearby as they waited for the sun to set.
A local photographer snapped a shot of them that evening sitting in the back of Samuel’s car, water bottles at their sandaled feet, facing one another. With wild grins, they look excited and hopeful in the evening light.
Slowly, and then with more persistence, a whole tree of fireflies lit up together, then the next tree, then the next, illuminating the forest like bulbs on a Broadway sign. Here it is, ladies and gentlemen, the greatest show on earth.