Thursday, December 10, 2015

Meditations on a Dead Worm

Dear George,
I was walking down Ludlow Ave. the other day when I happened upon the remains of a dead worm on the sidewalk.  It was a sad sight.  For an organism whose entire life mission consists in burrowing through the earth, dying on top of a concrete sidewalk is a lousy way to end it all. 

Because of growing up in the country, I was much more connected to worms in my youth.  I spent a lot  of time digging holes in the ground, helping my mother in her garden, getting bait for fishing, or just digging for the sake of digging.  I’d inevitably find four or more worms every shovelful.  One especially memorable activity was going to Riverside Cemetery at night after a heavy rainfall and capturing night crawlers on the front lawn.  They were big worms — up to eight or nine inches long.  They surfaced on the ground during the rain to avoid drowning.  You had to move silently and quickly to grab a nightcrawler because they’d dart back into their burrows the moment they sensed your presence.   

We think of worms as lesser creatures, but there are many more worms in the world than there are people.  Experts speculate that the number of worms in the world runs in the hundreds of trillions.  A British research station reports that a single acre of rich fertile soil contains about 1,750,000 worms. (5)  Even poor soil supports 25,000 worms per acre. That’s a lot of worms.  Even if we use an overly conservative estimate of 10,000 worms per acre, that means there are about 21,643 times as many worms in the world as there are human beings.  Moreover, worm’s lives aren’t fleeting.  Many varieties of earthworms live four to eight years in the wild.  Worms’ life expectancies are longer than rats, mice, toads, foxes, squirrels, eels, and rabbits. (3) 

Although they live in crowded circumstances, I don’t get the sense that earthworms are very social creatures.  You never hear about worms fighting or collaborating.  On the other hand, they do have busy sex lives.  Earthworms are hermaphrodites, meaning that each individual worm has both female and male sex organs.  Worms attract a partner chemically by emitting sex pheromones.  This usually happens at night and above ground.  A pair of romantically attracted worms line themselves up side by side, facing in opposite directions.  Then the worms hook up by attaching themselves to one another with bristle-like hairs, and both excrete a lot of mucous that forms a slime tube around their bodies.   Next each member of the pair secretes semen from its male organ into the other worm’s swollen female receptacle which contains its egg capsules.  Afterwards the two worms slip headfirst out of their respective slime tubes and create lemon-shaped cocoons which are buried in the earth.  Each cocoon contains up to twenty worm embryos.  The cocoons hatch two or three weeks later, and the newborns develop their own sexual apparatuses over the next couple of months.  Then the whole process begins all over again.  (2, 5) 

Nobody knows exactly what it’s like to be a worm.  Most earthworms spend the majority of  their time underground, so they inhabit a limited world.  They don’t have any eyes or ears or noses, though they have a tiny brain located in their heads just above their mouths and can chemically sense their surroundings.  Worms are sensitive to light and vibrations, can detect the presence of predators, experience pain, and are capable of simple learning.  (5)  And earthworms are powerful. Newborn worms can push 500 times their own body weight as they burrow through the soil, while full-grown adults push 10 times their body weight.  Worms spend most of their lives eating, taking in all sorts of organic matter, from leaves to decaying animal matter.  They excrete the digested material into the earth as nutrients.  (5)  According to the US Soil Conservation Office, a single earthworm can digest 36 tons of soil in a year. (4)  

Biologists note the immense role that earthworms play in enriching the organic environment.  Charles Darwin wrote, “It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.”  (5)  Earthworms are like little farmers, tilling the earth and promoting drainage.  They move the soil upwards and downwards, aerating it and distributing nutrients.   Aristotle described earthworms as “the intestines of the soil.”  (2)   Researchers have found that earthworms increase the yields of peas by 70%, spring wheat by 400%, and clover by 1000%. (4)  Moreover, worms have a lot of economic value as a commodity.  In a recent year Canada exported 370 million worms with an American retail value of $54 million. (5)

My father always had a great reverence for life, and, by the time that he reached his eighties, he had extended this outlook to all living beings — animals, trees, plants, insects.  When Katja was dismayed by a large spider in the kitchen at Farm years ago, Vic explained that the spider was his housemate.  Reluctantly he gave us permission to relocate the spider to the front porch.  I think Vic even gave up swatting mosquitoes.  I decided that, as one gets older, life  of all sorts becomes more precious.  In any case, that’s what I thought about the dead worm on the sidewalk.

Sources:  (1), “Earthworm”; (2), “How Earthworms Work”; (3), “Chart showing the average life spans of animals”: (4), “Earthworm benefits”; (5), “Earthworm”.

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