A teacher finds 'ahs' in the ooze
The effects of winter snow and spring rain are in striking contrast. Snow is a soporific: Its message is one of repose as it encourages the gentle drop of leaves, the southbound flight of the robin, and the migration underground of various small animals.
But rain is a life-giver, an awakener, a quickener. It comes down by the bucketful during spring showers, cascading from rooftops, dripping from the sopping canopy of the forest, and coursing briskly along curbs. This is water's spring drama. But I am more deeply drawn to its denouement: its understated collection in temporary places in the forest known as vernal pools.
Here in Maine, we are in the thick of vernal-pool season. Those of us in the know seize this opportunity to seek out the low places, the depressions along roadcuts, the hollows in the pine grove, the quiet, seasonal pools that differentiate themselves from ponds by their diminutive size and their lack of an outlet. Vernal pools exist for only a while, and certain creatures are even more keenly tuned to their transient nature than we are. In fact, their lives depend upon vernal pools.
I had almost forgotten what time of year it was when, a couple of weeks back, I took my college biology class on a field trip into the forest. Our interest was in the trees, so our eyes were directed upward. As we emerged from the woods, though, I caught a glint of sunlight off to the left. Suddenly, the field trip took a detour as I called my students together. "Look good and close at it now," I directed them, "because tomorrow it might not be here."
Vernal pools do not, of course, disappear overnight, but their lack of staying power makes every day of their existence a gift. That white pine over there will long serve as a landmark, and that boulder deposited about 10,000 years ago by the last glacier will likely persist for another 10,000; but this pool depends on the vagaries of the seasons. During these cool, wet days of spring, vernal pools lie in state, often underlain by bedrock or the tough, unbroken soil called hardpan, which prevents the water from percolating deeper into the earth. But come summer, with the advent of hot weather and sun, they evaporate without a trace.
So what did I want my students to note about this pool? The scene itself, pastoral though it was, had limited interest. "Look closer," I told them. "Who can tell me where the biology comes in?"
A few made cursory comments about insects and plants, but while these organisms abide the vernal pools, they don't depend upon them. I squatted at the water's edge and reached in. A moment later I gently lifted out a greenish mass with the consistency of jello. Embedded throughout the mass was the prize: the pea-sized eggs of some amphibian whose rhythms are perfectly in sync with the annual coming and going of the vernal pool.
My adult students paid due respect to the egg mass, but few had any inclination to touch it. For my part, I didn't want to put it down. It is the lot of the hard-boiled biology teacher that he or she lives for the "oohs" and "ahs" of his students that make science teaching so rewarding. But we were at semester's end, wrapping things up, and more than one student took the opportunity to check his watch.
Where does a teacher go for elation, wonder, and a wholesale return of enthusiasm for his modest efforts?
Kindergarten, of course.
A few days later, I returned to the vernal pool with my 6-year-old son, Anton, and two of his buddies. But for the life of me, I couldn't find any egg masses. Could they all have hatched? I put my diminutive biologists to work, describing what we were looking for. Within five minutes, my son was squatting poolside, an egg mass overflowing his small hands. As he, I, and his cohorts gathered round, we gazed deep into the jello, noting the developing young, each in its own little egg.
"Salamanders," I whispered, and they echoed my pronouncement with glee. We deposited the eggs in a pickle jar and made off with our precious gleaning.
The next morning, I arrived at my son's kindergarten class with microscope in hand. We set up the 'scope, focused it on an egg mass, and the munchkins lined up, quivering with anticipation. The exclamations were enough to fuel my pedagogue's conceit for many, many more miles of teaching.
In a week or so, once the salamanders hatched, we'd return them to the pool to complete their metamorphosis, and to insure that the drama would be played out for tomorrow's kindergartners, and for biology teachers willing to get their feet wet when winter turns to spring.