Bickerton, J. MaL Eva. 62, 718 (2806). 22. We thank L. Bayer, C. Vos, and A..C. Codti.Mcovoisin of Caruso) !moaner', as well as J. Laboot6 and 0. Tremblay of Universne Laval for technical supporL and E. Beth Hansen for diuussion and critical review of the manuuript. Also, we thank 1. R. Klaenhammer for providing the in