Let us praise the bold molds

t's that time of the school year again, the point in my college biology course when I must scramble, in the dead of winter, to grow fungi for my students. To most, it's not a very alluring notion, but to a biologist, the fungi are not only intriguing, but beautiful as well.

Delicate as cotton wisps, or tough as leather, each species of fungus has its own narrow range of growing conditions - temperature, humidity, light, and nature of the substrate - that allow it to blossom forth, often explosively. Who hasn't awoken on a damp autumn morning to find the lawn, or the shade under a pine tree, studded with mushrooms that weren't there the day before?

When conditions are just right, fungi will not be daunted. Many years back, a New Jersey man blacktopped his gravel driveway during the summer. The following fall, masses of mushrooms broke through the hardened asphalt. The fellow dug at them, poured lime over them, and even set them on fire, but still they grew. They had to. In a contest between man and fungus, the outcome is seldom in doubt.

Molds, mildews, mushrooms - fungi all. What they have in common is that they are composed of tiny fibers - hyphae - that in some places are packed tightly together, as in the mushroom, and in other places are highly diffuse, as in some species of bread mold. A determined and patient mycologist (one who studies fungi) once measured the growing tips of all the hyphae of a bread mold and found that, in a single night, it had grown an astounding one kilometer.

I often sing the praises of fungi to my students. Once they get over the unappealing sound of the word, they also warm to these organisms. Neither plant nor animal, fungi emulate both: They often look like plants, but, like animals, they must get their food elsewhere, usually from dead or decaying organic matter.

Ever wonder why the forest isn't littered with fallen trees? Fungi germinate as soon as (and sometimes before) the sap of these trees has ceased to flow. In fact, even while the trees were young and thriving, their leaves thirsting for the sun, they were literally blanketed with the microscopic spores of fungi. These spores had been biding their time, waiting for an opportunity to return the wood's nutrients to the earth.

In the days preceding our chapter on fungi, I busily prepare specimens for my students' study and (I hope) delight. Fungi are big and small, pale and brilliant-orange, threadlike and buttonlike. Most important, they will "attack" anything of an organic nature. In fact, there is evidence they will grow on almost anything that contains carbon, whether it was once alive or not.

A friend of mine who had moved to Galveston from the northern Midwest once left her Texas home for a week and made the mistake of turning off the air conditioning. Upon her return, fungi had eaten away the rubber seal on her refrigerator door and had begun to consume the food within. Talk about opportunists.

When detractors sniff at my affinity for fungi, I remind myself - and them - that I am in good company. Canadian poet Frederick George Scott once wrote (albeit in a state of despondency), "Day by day the moulded smell/ of this fungus-blistered cell." And the celebrated Seamus Heaney, in his "Personal Helicon," spoke fondly of them:

IAs a child, they could not keep me from wells,

And old pumps with buckets and windlasses.

I loved the dark drop, the trapped sky, the smells,

Of waterweed, fungus, and dank moss.

And for those whose reading is restricted to whatever glimmers on the computer screen, there is a wonderful site called "The Norwegian Fungus of the Month."

I take a piece of bread, some orange rind, a dab of marmalade, and even a piece of leather from an old shoe. Each of these I place in its own petri dish. I add a mist of water from an atomizer before setting the covers down. Then I put these dishes in the darkness of a paper bag and set them on top of the refrigerator, a place of subtle warmth.

After a week, I open the bag and - voilà! - the desert has blossomed like a rose, or rather, like a mold, in colors ranging from black to orange to blue-green. I have my fungi, and I couldn't be happier.