By hook or by crook...

Autumn is a time of fruits and seeds, which use a variety of strategies to disperse. The hook-like prickles of the seeds of burdock, herb bennett, hound's-tongue, cleavers and agrimony (pictured here) attach themselves very effectively to animals' fur and items of clothing, as pet owners and keen hikers will no doubt know.

These types of seeds gave rise to the invention of Velcro, a classic and early example of biomimicry. The hook-and-loop fastener was conceived in 1941 by Swiss engineer, Georges de Mestral. The idea came to him one day after returning from a hunting trip with his dog in the Alps. He took a close look at the burrs (seeds) of burdock that kept sticking to his clothes and his dog's fur. He examined them under a microscope, and noted their hundreds of "hooks" that caught on anything with a loop, such as clothing, animal fur, or hair. This sparked the idea of binding two materials reversibly in a simple fashion if he could figure out how to duplicate the hooks and loops.

For many years after it was developed, Velcro was restricted to rather technical and utilitarian clothing, such as astronaut's suits and ski-wear. Now Velcro is widely used in all sorts of applications - Velcro shoe-straps are a particular boon for those with young children or anybody who is unable to tie shoelaces through age or disability.

Thanks to everyone who sent good wishes to Alex yesterday. He is much better after a long sleep, and even managed to eat his evening meal. I suspect his illness was caused by Norovirus. Apparently this can be present in seafood, and I suspect he must have eaten a contaminated prawn, that hadn't been cooked for quite long enough on the barbecue. As far as I know no-one else was ill though, so he was just really unlucky. Chris and I are still OK - the incubation period is very short so we should be in the clear after tomorrow!!