From Fingertips to Papillae: Marcello Malpighi on the Sense of Touch

In his two works on the tongue and the organ of touch (De lingua and De externo tactus organo), both published in 1665, Malpighi revealed the existence of tiny structures called “papillae” that, like nerve receptors, he argued to be responsible for taste and touch perception. The papillae represented the extremities of nerve branches that, emerging from the skin, were directly accessible to external stimuli. This discovery was the result of a wealth of evidence collected during his stay in Messina as well as Malpighi’s ongoing exploration of ancient and early modern sources. By offering a new interpretation of the operations of these sense organs, Malpighi challenged the Aristotelian notion of a “medium” for senses and also questioned the debates surrounding the structure of the tongue and skin that characterised anatomical research in the sixteenth and early seventeenth centuries. This chapter explores how Malpighi approached touch through a series of lectures on skin and membranes in 1663–1664 and how this paved the way for his demonstration of the existence of “tactile papillae” in De externo tactus organo. Drawing on Malpighi’s personal unpublished notes, lavishly enriched by drawings, this chapter aims to analyse how Malpighi developed his research on touch, highlighting his dependence on previous research on the tongue, and how his conceptualisation of touch perception as “unmediated” and strictly related to the role of papillae was highly debated by his contemporaries.