the Beast Puppet and Mask Theater of Minneapolis; Arm-of-the Sea Theatre from New York State; Snake Theater from California; and Shadowland Theatre of Toronto, Ontario. These companies, and others, have a strong social agenda, and combine masks, music and puppetry to create a visual theatrical form. Another route masks took into American Theatre was via dancer/choreographers such as Mary Wigman, who had been using masks in dance and had emigrated to America to flee the Nazi regime. In Europe, Schumann's influence combined with the early avant-garde artists to encourage groups such as Moving Picture Mime Show and Welfare State (both in the UK). These companies had a big influence on the next generation of groups working in visual theatre, including IOU and Horse and Bamboo Theatre, who create a theatre in which masks are used along with puppets, film and other visual forms, with an emphasis on the narrative structure. Functional masks Masks are also familiar as pieces of kit associated with practical functions, usually protective. There has been a proliferation of such masks recently but there is a long history of protective armour and even medical masks to ward off plague. The contrast with performance masks is not always clear-cut. Ritual and theatrical masks themselves can be considered to be practical, and protective masks in a sports context in particular are often designed to enhance the appearance of the wearer. Medical Some masks are used for medical purposes: Oxygen mask, a piece of medical equipment that assists breathing. Anesthetic mask. Burn mask, a piece of medical equipment that protects the burn tissue from contact with other surfaces, and minimises the risk of infection. Surgical mask, a piece of medical equipment that helps to protect both the surgeon and patient from acquiring infection from each other. Face shield, to protect a medical professional from bodily fluids. Pocket mask or CPR mask, used to safely deliver rescue breaths during a cardiac arrest or respiratory arrest. Protective Protective masks are pieces of kit or equipment worn on the head and face to afford protection to the wearer, and today usually have these functions: Providing a supply of air or filtering the outside air (respirators and dust masks). Protecting the face against flying objects or dangerous environments, while allowing vision. In Roman gladiatorial tournaments masks were sometimes used. From archaeological evidence it is clear that these were not only protective but also helped