Life on a limb

We got smacked last week--I still step over a downed line when walking to school, and the curbs are lined with life-like tree limbs. Just seeing all these leafy zombie branches edging the asphalt gives me an odd joy.

I wonder if other biology teachers feel the same way.

The storm was a great reminder why trees scurry to drop their leaves in the fall. Trees that dropped their leaves before the storm, ceding the dying sunshine to their leafy neighbors, stand smugly over the debris of their neighbors.

A couple of mornings ago, on a gray morning so still I felt like an intruder, I stopped to watch a leaf slowly wobble its way to the ground, silently rocking to a lullaby, as though choreographed by a Great Designer.

Watching the leaf fall, its season done, was an obvious reminder of what awaits, but it did not fall for me. The leaves littering the ground suggest that leaves fall all the time without my awareness.

It was the day after the Day of the Dead.

The idea that a leaf's gentle fall cold be choreographed by some Great Designer is a comforting conceit, and could serve (for some) as evidence of אהיה אשר אהיה --as gentle and powerful a description of whatever this whole whatever is.

But all that's unknowable, and I only have so many hours to play, so my mind wanders back to the biology, to what we do know, enough for me. More than enough.

***

There is much to be learned from  observing a leaf. A young child can easily discern the thickening at the base of the stem, the veins traveling through the leaf, the various shapes of leaves, the similarity of leaves from a given tree.

That same child can see that some trees give up leaves before others, and that some never seem to give them up at all.

To do this, though, the child needs time to do what looks like nothing. Untestable nothing. Not a whole lot of money can be made from children doing nothing.

***

If you look at the end of the stem of a fallen leaf, it will be smooth, as though the leaf were designed to be sliced off.

As the light fades and the leaf no longer has the energy it needs to make new chlorophyll, the green pigment that catches light, cells actively work to prepare for a leaf's end. The break is not accidental. The leaf remains attached to its twig by the remnants of its main veins. That the vessels are called xylem, and that we require children to memorize xylem, tells us nothing about life, nor biology.


What might interest a child is that cells actively prepare for their own death. What might amaze the same child is that our cells do the same thing--it's part of how we develop fingers.

I happened to be walking by a tree on a still day when the thin threads of xylem finally gave way, at an age when death feels more real than it did decades ago.

A child walking by the same tree might rather run through the leaves already fallen, rustling through the warm leaf smell that reminds her of Halloween, of Thanksgiving, of Grandma--but not death.

However a leaf affects a child, she must first be aware it exists.

Last time I looked, there was not a hint of a leaf's leafiness in our textbook.

The fetal hand is from the Gerontology Research Group--they got it from an IMAX movie "The Human Body" produced by BBC et al.