As is well evidenced in the history of biosemiotics that opens this volume, the work of Estonian naturalist and experimental biologist Jakob Johann von Uexküll occupies a singularly prominent position in the contemporary attempt to develop a biological science of signs. "When we talk about [Uexküll's bio-analytical concept of] Umwelt," writes historian of ideas John Deely, "we are talking about the central category of zoösemiosis and anthroposemiosis alike" (1990: 120). Accordingly, Thomas A. Sebeok, whose revival of Uexküll's all but forgotten work was integral to the launching of the project of biosemiotics proper, never failed to acknowledge his debt to the man whom he considered 'single-handedly brought biosemiotics about – avant, so to speak, la lettre – [with his] wholly unprecedented, innovative theory of signs, the scope of which was nothing less than [the scientific investigation of the manifold of] semiosis in life processes in their entirety" (1998 [2001]:168–169).