When I was young, I met a coarse ruddy man named Blood who wore bib overalls. His rattly car was red with iron rust. I thought Blood an awful name. As bad as Guts. I didn’t know that the word blood comes from “blut,” for “blow,” referring to the way blood may be brutally shed, but I was glad it wasn’t my name. The prettier words sangre, sanguine, sangria refer to the blood’s rich color. Name me Sanger any day.

Later, I shed blood at my loss of virginity; drops of sanguine tears signified the beginning of the heavy and heavy-hearted responsibility of sexuality and its attendant difference between the sexes. Mature, females are bloody; males are spermy, smelling of hormones and the fructose nourishment for the squiggling cells they make. Males miss the fragrant female clockwork curse of reproductive years, miss the scrubbing of rust-stained panties with cold water (quick, or it sets), the blood of miscarriage, the blood of birth, the confused splattering of menopause. They miss the constant reminder of the smell of blood, the smell of life. Perhaps that is why males have searched out blood through hunting, while females have had quite enough of it, and would rather dig anemic roots.

Last year, my menstrual blood would not cease. The doctor considered the periodicity that had become constant: “Have you been stressed in any way?” he asked. “By life,” I said, “by living. But Fm in practice.” “Some women’s bleeding,” he said, as he wrote loopy words on the prescription pad, “reacts to tiny stresses. Other women”—he ripped the sheet expertly, looked up triumphant— “are made of iron.”

Synthetic hormones tamped the flow. The stream slowed. I swelled. I bought many boxes of absorbent pads. Life leaked. My blood and I were constant companions. My white dress hung forlorn, my black dress became the garb of choice. I douched, showered twice a day. But my nose told me a butcher shop was near.

As I exsanguinated, sexuality waned. I grew weary. Come in for a blood test, the doctor said. I sat in the desk, extended my left arm. The technician tied a piece of rubber tubing around my upper arm to retard venous return. The brachial vein ballooned predictably. She dabbed alcohol, produced a fat syringe. “This will sting,” she said. It did. Unlike the bloodsucking parasites, the needle has not evolved a painless bite. Somewhat sadly I watched my blood, my living barometric fluid, my liquid tissue, sucked into the tube.

In two days, the nurse called. “Take iron,” she said. I did.

I remembered my technician days with the salt marsh sparrows. A scientist wondered how they drink salty water without dehydrating their blood, without becoming pieces of feathered jerky. He caught them and gave them solutions of salt water to drink, then measured the saltiness of their blood. Indirectly, he measured the efficiency of their bodies to concentrate and excrete salt. I worked for him and drew the sparrows’ blood. I reached inside the cage and took a bird’s head between my two forefingers and wrapped my thumb around its tiny hot body. I raised and spread its wing. With sharp scissors, I snipped the vein and touched the wound with a capillary tube. The blood climbed in. I staunched the flow with styptic, returned the bird to its salty drink, took the telltale blood for study. Later, the experiment done, the scientist gone, the birds were left to me. I carried them home, a cageful. The scarred underwings did not affect the beauty of their songs. Short-lived, however, one by one they died, and I plucked each cold limp body from the cage and buried it.

So as a teacher I was ready each semester when my students and I examined blood. I used the exercise for relevance. Teaching hospitals have a Human Subjects Office. A permit was required to collect the birds. I required no permit, I could only encourage cooperation. But group pressure helps. Is what we’re doing ethical, justified? Where does human experimentation begin? What about examination of a fingernail, a piece of skin? Where does consent begin? When does a practice become invasive? Should blood donors, organ donors, human subjects be paid, should desperate people be allowed to sell their bodies? Aha. Paradoxically, an education—the students scratched their heads—contains more questions than answers.

For the examination of blood, then, I required the tacit permission of my human subjects. The fear of AIDS, I fear, may have altered feelings toward this standard laboratory test.

Great is the aversion to, yet fascination with, one’s own blood. As a child I had chronic nosebleeds. I needed only to sneeze, and out came the brilliant blood. I dripped over the sink. Whence did this fluid come, and why? Was it the lubricant of gears, of the motor of my heart? Later ï saw chickens beheaded, a pig butchered, a careless toad flattened by a car, a calf born and licked. Death and life. Bloody, all of them. Like me.

The sight of blood recalls pain. Red incites. And so I understood the fear and excitement of the student blood-letting. Trepidation ensued: just to get a small drop from a middle finger of the left hand. Or of the right hand, for left-handed persons. I, the teacher, was calm.

The alcohol swabs were brought forth to disinfect the fingers. The air smelled of a hospital. Students held their cleansed fingers upright, in a modified obscene gesture, while they studiously read the laboratory manual, turning pages with the opposite hand, sneaking glances at others. The title of the laboratory lesson was Blood Cells. The double O’s loomed large, like eyes. They asked silently, Who will be first to draw the blood? Who will be ready?

The hermetically sealed lancets appeared. I busied myself with the stains, the microscope slides.

Will the teacher do it? Of course I would. It is easier to draw blood from another person than from oneself, although medical literature attests to the strange men who performed appendectomies and other drastic surgical procedures on themselves. I thought of the man who catheterized his own heart, as I stripped the aluminum to reveal the shiny point, as I confidently pricked my own finger, for dignity’s sake, for powers sake. I was in charge. I was not queasy. Remember menstruation, remember all those nosebleeds?

Fingers differ. One was attached to a guitar player and was huge, with calluses. I knew the lancet would bend, and we’d have to try again with another, a little to the side. Another fingertip was spatulate; another pale, so pale, tapering to a point, and I doubted that it could contain anything but thin bone. Several fingertips, of course, were decorated with long fingernails, fluid catchments, some white, some painted blood-red.

A quick jab always brings forth a drop, red and shiny as a miniature bing cherry, and I am always amazed as the drop wells up, the molecules hugging each other, held together by the physical, adhesive forces that hold together a drop of water. Blood has some of the properties of sea water, but also wild properties of its own. We came from the sea, but we are more than sea. The blood is stickier, thicker, more viscous than pure water. It gets stickier as, shocked, exposed to air, it dries. We had so many things to do with the blood.

Quickly, I turned the finger, nail up, print down. I squeezed, milked the finger. Gravity helped. The drop plopped onto the glass microscope slide, plopped onto another slide, plopped onto a special paper for testing redness, thus hemoglobin, thus iron. Iron plus oxygen is red. Some was sucked—thwip, thwip, thwip—into a capillary tube for centrifuging, spinning, separating into cells. The cells—”formed elements,” we call them—are heavier and fall to the bottom. On top the liquid, the yellowy plasma—”straw-colored,” according to the manual. Even the plasma is not all water—eight point five percent is something else, created by life. My students looked at the proportion of cells to liquid to determine if they’re normal: 45 percent to 55 percent. If they weren’t they’d be home in bed, or in a hospital, having a transfusion.

I covered the wounded finger with the swab, with cotton, and turned my attention quickly to the blood. Spread it gracefully on the microscope slide with a second slide, I instructed. On the other, follow the instructions for staining. You’ll see why. Neatly, neatly. Step by step. Avoid air bubbles when applying the thin glass cover slip, I said.

The red blood cells do not need stain. We looked at them quickly. They flow, float orange, in their liquid plasma. They are shaped like cinnamon candies, like the “belly burners” given me by a coughing microlepidopterist, like tires on rims, thick at the edges, thin in the center. The word for them is biconcave. An example, I said, of form and function. An adaptive form for their jobs—increased surface area for pickup and delivery of oxygen molecules.

Using a little iron, some amino acids, the bone marrow forms the blood cells at the rate of two million per second. You have replaced them by now, I said, with relatives, with kin. These cells are advanced—their ancestors were normal nucleated cells, but the mature children, in their decision of specialization, their occupational commitment, discarded their past, extruded their nuclei, spat out their bags of DNA, their very control centers, to make room for more of what they carry: hemoglobin.

Cells with a death wish give us Hfe. With the nuclear extrusion comes the death sentenœ—no more dividing: 120 days, just 4 months, to live. During that time each biconcave cell goes on a long, long trip, around and around its world, thousands, millions of times, massing in the large veins and arteries like people on Tokyo streets, clicking together single file in the capillaries, like a roll of belly burners.

streets, clicking together single file in the capillaries, like a roll of belly burners.

Its iron-containing pigment hemoglobin snatches oxygen through the thin membrane of the lung capillaries and ignores the more numerous molecules of nitrogen gas. Oxygen is what it wants, oxygen is what it gives away to the body’s cells, oxygen is what it gets more of. The cells are cycling automatons, but they see different sights, take different routes as they move through the capillary networks.

To show the students how the blood courses, I went to the pet store and bought a goldfish, a healthy one with good fins and tail. I brought it back to the laboratory in a plastic bag full of water, and let it swim free in an aquarium, until the students came in with their books and bags. Then we got out the microscopes and the thin little board with a hole in it. I wetted a paper towel, and folded it into a strip about as wide as the goldfish. I remembered the little fish net, to catch the goldfish, and I wrapped the carp quickly. Its tail stuck out. I quickly put it under the microscope, and adjusted the field of view.

The tail is thin. Light passes through. Visible were dozens of capillaries, full of red blood cells, streaming, streaming, streaming, this way in one vessel, that way in another. I told the students to look quickly; the fish’s tail will get hot and dry with the light. Desiccation is the biggest threat to life. After everyone saw the blood, I unwrapped the puzzled fish like a tamale over the tank and it splashed in. We fed it a few fish flakes, gave it a rest and repeated the procedure later. I sent it home with a student who had an interest in pisciculture.

Another way: I asked the biology department to order a frog. I wrapped it in a wet towel, too, with its feet sticking out. It looked ridiculous, but it did not struggle. I spread its toes and thus the webs, the membranes between them, over the hole on the little board, which is known as a “frog board.” I pinned the foot down with dissecting pins. I looked through the microscope eyepiece, focused. More red blood cells, coursing, coursing, close together but fast, like traffic moving rhythmically on the Los Angeles freeway. A little hesitation sometimes, but no jams.

The frog engineer has made the capillaries the diameter of a single cell. Frog cells, I told the students, are nucleated. The frog also gets oxygen through its wet skin. I put the frog back in the bucket of water and watched it look at me for a moment. Later a volunteer turned the frog loose in a pond, perhaps at the zoo. It may have been homesick, but we hoped its feet healed, it caught a few insects, and died of natural causes.

Then I talked of hemoglobin. A molecule with a tail. I drew its structure on the blackboard. Heme, the iron-containing ring, and globin, protein. Two hundred and eighty million molecules per red blood cell. Students wrote this information using their unpricked fingers. In structure, hemoglobin is very much like the green pigment chlorophyll of plants. An amazing thing, but not so amazing. Evidence for the interrelatedness of all life. A unifying principle. I remembered to mention the big picture. I mentioned the cyanide-based oxygen-carrying pigments—the green stuff that squishes from an insect, the stuff of a lobster. Works just as well, but the students always say yuck about blood that is not sanguine.

Lastly, on the stained slides, we began our search for other components of the blood, the less numerous components, the lovely, lovable leukocytes. They are the white blood cells that must be stained to be seen. Also cast from the bone marrow, and from tonsils, lymph nodes, the spleen. But different from the biconcave proletariat. These are the individuals, the wandering cells of the immune system, the warriors, the knights, the crusaders, the wrestlers, the gobblers, the tarbabies, the cleanup crew. These are free cells, cells that are not confined to the body’s vessels, but slip in and out to go where they are needed, mercenaries for the current campaign. Individuals, they keep us individuals; they both attack and produce an arsenal of antibodies that ward off attack.

Years ago, one of my classmates died of cancer of the blood—leukemia. Her white blood cell production had gone awry. When too many are made, they choke the vessels. To live well, the body stays in dynamic balance, in busy equilibrium, in proportion, in moderation with all things.

We saw our first white blood cell, a neutrophil. Two-thirds of the white blood cells are neutrophils. Each neutrophil has a lobed nucleus, strung together like a hot-dog-shaped balloon that has been twisted into portions. A fat place, a skinny bridge, another fat place, another skinny bridge, and on and on. Outside the nucleus, the cytoplasm is foamy. “Granular,” reads the manual.

We looked again, among the teeming sameness of the red blood cells, and saw a lymphocyte. Smaller than the neutrophil, although no white blood cell is as small as a red blood cell. The telltale signs: a big, round red nucleus, surrounded by a thin rim of blue cytoplasm. A deviled egg, colored wrong. One-fifth to a quarter of the white blood cells, I noted, are lymphocytes.

We kept looking. Next we saw a monocyte, a giant cell with a giant dumbbell nucleus. Three to eight percent of the white blood cells are monocytes. Unmistakable. And the eosinophils, two to four percent, those that love the red stain. More lobed nuclei and their cytoplasm splattered with red.

Now the search began in earnest. “If you find it,” we read in the laboratory manual, “notify your instructor.” I looked at several slides, discarded them. Where were they, those blue-dotted cells with the pale, ethereal nuclei? Less than one percent of the white blood cells, they are elusive. Finally, a lonely one appeared. The instructor notified the students. “Come, look, everyone,” I said. “Do you see the subtle differences?”

The students looked, were engaged, as engaged as possible. I became aware of my breathing, of providing oxygen to my cells, of the blood-production factories of my inner bones. I was flooded with a strange ecstasy brought on by examining bits of life. I felt an electrical frisson, a quivering depolarization of my skin, as the cells connected frogs and fish and birds and students. I am crazy, I thought, but harmless. I have seen mitosis in a pizza, parameca in a paisley tie. I see my love life in the cells.

With stain, the white blood cells explode with orgasmic Fourth-of-July color. The rarest are the most precious. I heard a soft voice in my ear, whispering carbohydrate names: sweet stuff, honey, sugarbush. In the common, I thought, is wonder. In the rare is beauty.

I smiled sanguinely and told the students they were in the presence of beauty, that their own bodies are beautiful precious things. Two students looked up from their microscopes, startled. They were thinking that I should be an English teacher, because only English teachers find things beautiful. Science teachers are cold, and talk of facts and theories. One or two of the students probably began to worry that I would require correct spelling on the exam.

The students understood the red blood cells, but the white blood cells still looked alike to them, and would continue to look alike until they had studied them for a time. For some students, the white blood cells will look alike forever.

The students began to gather up their bags and books and disappear, slipping by ones and twos out the heavy door. When the student whose bright smile betrayed his love—for me or for biology—finally left, I erased my notes and drawings from the blackboard and wiped my hands on the sides of my laboratory coat. I am always surprised by the neatness of my script, the roundness of my circles. From the laboratory tables I picked up scattered wipes with spots of now-browned blood. The blood on the uncovered slides was dried and cracked like mud; the tiny desiccated ponds were no longer vital. I tossed the evidence of our mortality into the garbage can, picked up my own books and notes and turned out the light. I left the back way, hanging my laboratory coat in a closet in the central laboratory, where the light was always on, where shelves were packed with charts and models and buckets of specimens, and where three brown-blooded cadavers slept in their body bags.

As I emerged into sunlight, I thought of a poetry class I took long ago: “Use strong words,” my teacher said. “Darkness is a strong word. Tunnel is a strong word. Blood is a strong word.”

About the Author

Jill Carpenter

Jill Carpenter, a biologist and journalist, is the author of “Senses and Sensibilities” (John Wiley & Sons) and has edited a collection of poetry and prose about frogs and toads.

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