Each summer when I was still in elementary school the Pitts family joined mine to spend two weeks at a public campsite in the Adirondacks.One year about a month before we left one of the Pitts daughters, Edith, fell in our backyard, cutting herself on her thigh. The nasty wound
became infected and, despite doctor's treatment,remained swollen, discolored and ugly when we headed for the mountains. On those holidays we youngsters spent much of our time in or near the water and on one morning, Edith suddenly screamed and ran from the beach to our parents.

Not knowing what had happened, the rest of us followed.

A black caterpillar-shaped creature had attached itself to her wound and Edith couldn't get the slippery worm off. My father identified the
animal, now swollen to the size of an inch-long cigar stub, as a leech. Dad quickly lighted a match, blew it out and touched the still hot end
against the leech. It immediately let go and, much to the consternation of us children, he threw it back into the lake.

Although the episode made our swimming less attractive, the leech deserved not to be killed because we soon found that it healed Edith's
wound. Evidently it drew off the clotted blood that had delayed her recovery.

I thought of that incident when I came across John Colapinto's article, "Bloodsuckers", in the July 25, 2005 issue of The New Yorker. He
describes in that essay how leeches (and maggots as well) have become important adjuncts to modern surgery. (An earlier source is Richard
Conniff's August 1987 Discover Magazine article, "The Little Suckers Have Made a Comeback.")

Colapinto quotes microsurgeon Bruce Minkin: "When you're sewing on a finger, it's relatively easy to join up the arteries that pump blood
into the digit, because they're big and they've got thick walls. But it's tougher to connect the tiny veins that drain the blood away from
the finger and back to the heart." Reattaching those veins is, according to Joseph Upton, "like sewing together strands of wet toilet paper," and
if they aren't correctly connected, the blockage will cause the operation to fail.

It is here where the bloodsucker comes to the physician's assistance. In order to withdraw the blood it seeks -- only about two teaspoons -- the
leech injects a natural anti-coagulant into the wound. This creates a kind of artificial circulation that gives the finger a chance to grow new vein attachments and the wound to heal.

Leeches have been employed for medical purposes since about 1000 B.C. and their use -- almost exclusively for bloodletting -- peaked in the
early 1800s when Germany alone exported about 30 million a year. Practices changed, however, and their application dropped to near zero
in the first half of the 20th century. Then in 1960 two Slovenian physicians wrote about their successful use of leeches in surgery and
things began to change -- but very slowly.

The recent history of their use for medical purposes centers around two people. The first is Roy Sawyer, the recognized world authority on the
over 650 leech species and author of the definitive three-volume study of them, Leech Biology and Behaviour (Oxford University Press, 2004). A Charleston, South Carolina native, Sawyer received his doctorate from
the University of Wales and stayed on there to grow leeches for use largely in neurological studies. Sawyer's company was making little
headway until 1985 when the ear of a Boston five-year-old was bitten off by a dog.

And that brings us to the second person. Reconstructive plastic surgeon Joseph Upson of Boston Children's Hospital attempted to reattach the youngster's ear. Despite his twelve-hour operation, the ear began to turn blue-black from congested blood. Clearly all his efforts were
unsuccessful and the organ was dying.

Upson decided to try applying leeches. He didn't tell his colleagues -- "Are you kidding me?" he remarked later. After a frantic search he
located and contacted Sawyer in Wales at Biopharm and Sawyer's wife drove a batch of 30 leeches to London to be flown to Boston. Within
minutes of Upson's attaching the first two leeches to the boy's ear, it began to turn pink and just days later the ear was completely healthy.

This was the first successful reattachment of a child's ear and the procedure gained national publicity. Now plastic surgeons worldwide are
employing leeches in their work. As a result today Biopharm distributes about 5000 leeches a month through its international centers.

The appendages now being reattached with the assistance of leeches -- the process is technically called hirudotherapy -- include not only ears but also fingers, hands, toes, legs, noses and scalp tissue.