My father was a scientist, and I grew up in his laboratory. Maybe I am like him, but he is not like me. My father was a physicist, while I am a biogeochemist. I live to study plants, and he has never had more than a generic interest in biology. And yet my father spent the better part of his 70th summer observing a single tree, and in the end, gave me a hundredfold more than what I had asked for.

My father can no longer write. He is 92 now, and he cannot make his hands work. He cannot walk, or even stand, and he can barely see. He is not certain what year it is, but he is sure that I am his daughter, and that my brothers are his sons, and he treats us just as he always has. He still knows me, and for this I am grateful.

When I visit him these days, we sit in the same house that I grew up in, but we don’t talk about science anymore. Just one year ago we could, and he explained friction and inertia to my son, letting him push on his wheelchair to demonstrate.

But numbers confuse him lately, and so we talk about poetry instead. My father’s schooling during the 1930s was heavy with memorization; eight decades later, he is reaping the benefits. It is positively amazing to see how much of Longfellow’s forest primeval he remembers from “Evangeline,” indistinct in the twilight though he may be.

As with many Midwestern families, great distances pervade our relationships — both literally and figuratively. We never really talk to each other; instead we box up our hurts and longings and store them for decades, out of sight but not forgotten.

It is summer in Minnesota as I write this: four blessed weeks of birdsong and fireflies made all the more beautiful by the fact that it will not last. This year my father and I have spent it inside, reading.

I take out our old tattered Giant Golden Book of Aesop’s fables, and I start with the stories about dogs because they were always my favorite. I recite the text with the inflection my father used 40 years ago when I was 6, and still pretending that I couldn’t read, so that he would not stop reading aloud to me. When I near the end, I pause, and my father recites the moral word for word.