Originally published in 1988, this was the first book-length study ever to be published on the subject of sign language as a means of communication among Australian Aborigines. The work presented in this book filled an important gap in Aboriginal ethnography and linguistics. It also marked a major advance in the understanding of the relationship between medium of expression, code structure and communication; the processes by which spoken language may be represented in a non-vocal medium; and native speaker awareness of spoken language structure. Based on fieldwork conducted over a span of nine years, the volume presents a thorough analysis of the structure of sign languages and their relationship to spoken languages.