If, as a child, you enjoyed paddling around in streams and ponds, looking for sticklebacks or minnows or, in season, frog spawn, and maybe newts, you would soon become aware of leeches. Things to avoid. You were told they would suck your blood. They could take on various shapes. You might even believe that the chemists kept them in those tall, coloured bottles that were their hallmark. Now an article informs us that big chemical companies - Glaxo Wellcome is mentioned - have funded a local countryside project to look after a site in Romney Marsh, Kent, in particular, where breeding grounds of leech have been found. They can contract and extend their bodies and have a sucker at each end. "Motion over a solid substratum is by looping, often with sinuous, snake-like movements during the extension phase. Some species can swim by graceful undulations of the body." Some suck the blood of fish if they can get them, others prey on various vertebrates and invertebrates - worms, molluscs, insect larvae. Only two species, both very rare in Britain, are capable of feeding on human blood (Collins Field Guide to Freshwater Life.) But that fine, pocket-sized magazine The Countryman tells us that they are back in demand, after some time, for an article avers that there is a demand among surgeons for the medicinal leech from plastic surgery units and surgeons who reattach severed limbs. Once attached, the leech will make the blood flow more freely to the affected area, ensuring grafts are successful and re-attached parts of the body will not wither and die.
The article informs us that specialists at the Queen Victoria Hospital, East Grinstead, can call on their own pharmacy, which supplies about 350 per year, costing £10 each. Leeches' saliva has an anti-coagulent which thins the blood and prevents clotting. Using leeches is an ancient practice. (A physician was at times called a leech. The dictionary notes: "now archaic (chiefly poetical) or jocular." Leeches, the article claims, may in the past have killed as many people as it cured, in cases where patients were starved and then had too many leeches applied. It is said that Hitler's doctors were "stunned" when he demanded that leeches be applied to his ears, but it is likewise said the treatment stopped them ringing. Stalin was not so lucky. He "was dying when they were put on him and had absolutely no effect." Next stage is to see if the saliva of the leech can be reproduced chemically.