In this article, the role of abductive reasoning within Peirce's diagrammatic reasoning is discussed. Both abduction and diagrammatic reasoning bring in elements of discovery but it is not clear if abduction should be a part of a fully developed diagrammatic system or not for Peirce. This relates to Peirce's way of interpreting abduction in his later writings. Iconicity and perceptual elements as a basis for discoveries are analyzed, both in deductive and abductive reasoning. At the end, the role of modern ideas of distributed cognition applied to the Peircean scheme is shortly delineated.