Bacteria adhere to and colonize almost any surface. Within minutes after sub merging a solid object in seawater or freshwater, the surface becomes colonized by adherent micro-organisms, and the earliest organisms to adhere are bacteria. Adherent colonies of bacteria have also been observed on particles of sand, soil, other bacteria, plant tissues, and a variety of animal tissues. Shortly after birth, the skin and the mucosal surfaces of the upper respiratory tract and the gastro intestinal tract of animals and man become heavily colonized by a variety of adherent bacteria which persist in...