I am not sure if I buy this one. Suppose that there was an epidemic of measles in New York. Would we conclude that this was because New Yorkers were eating one anothers' brains? Yet we jump to this conclusion in New Guinea because two stories, the story about cannibalism and the story of prion transmission, fit neatly together, and the cause of mad cow disease (bovine spongiform encephalopathy, or BSE) and its human equivalent, variant CJD, has thus apparently been identified. Cannibalism as an explanation is suspect because ritual cannibalism (as opposed to survival cannibalism) so often, if not always, turns out to be a fabrication (see Arens "The Man-Eating Myth Anthropology and Anthropophagy" circa 1978.) The prion transmission hypothesis was suspect for a long time but was adopted finally before even one in vitro experimental demonstration of its workability as a means of transmission. Prions are peculiar entities; they carry just enough information to do the job required of them but they are small enough to get through the blood/brain barrier which would normally protect us. So in a sense they had to exist if the blame for vCJD was to be laid at the door of poor feeding methods. I can't remember how many thousands of cattle were sacrificed in the UK, the worst hit country for BSE, but it was reminiscent of biblical times. When the purge was over we were pronounced whole again but only very slowly and reluctantly were we allowed to once again export meat to continental Europe. The trouble with thinking you have found the criminal when you haven't is that he may still be at large and liable to strike again. There are other hypotheses of BSE, and its human analog. One was based on the fact that VCJD sufferers were often farmers, veterinarians and the like, or in a few cases worked in garden centres. The common factor in these people was exposure to organophosphates, which is often of course true of cows as well. Dick Bird -----Original Message----- Ben Balzer said As for the brain and mad cow disease, well now you've got me started. One of the first proven prion brain diseases was kuru in the New Guinea highlands. This was proven to be due to the ritual eating of the brains of deceased relatives. Cessation of this practice has stamped out kuru. Thus it is entirely predictable that when agricultural economists decided to feed cows the brains of their own deceased relatives, that they had created an opportunity for a prion disease to enter the cycle, and be concentrated upwards, exponentially affecting more cows. In due course this has happened.