Dr Arendt andhis colleagues compared the molecular fingerprints of the nerve cells of Platynereiswith that of a vertebrate, the zebrafish.

As he wrote a word on his card and waited for anenvelope he glanced about the embowered shop, andhis eye lit on a cluster of yellow roses.

Michael Thorpe andhis colleagues at the National Institute of Standards and Technology, and theUniversity of Colorado, both in Boulder, have been looking for somethingbetter.