Silas Weir Mitchell (1829-1914), justly regarded as one of the founding fathers of neurology, published accounts of phantom limbs in the 1860s and 1870s,1 around the time that neurology was emerging as an independent clinical discipline (although earlier accounts of phantom limbs are recognised2). Phantom limbs are most often observed in the context of amputation, but reports of extra limbs occurring without amputation have also appeared. Two brief cases are presented here to illustrate the clinical heterogeneity of the supernumerary limb, the possible pathophysiology of which is briefly considered.