I'd like to know more than I've learned by twice reading the estimate of nos. of waterfowl leading healthy lives on the flyways because they have non-tox in their craws. I'd like to know more about the action of the craw or crop in producing lead poisoning. Is it a matter of mechanical abrasion, a milling operation, so to speak? What is the connection to field corn? Another relatively hard object which must be ground? Please enlighten me.

jack