A variant of Priffer's classical proof of Cayley's theorem on the enumeration of labelled trees counts the nilpotent self-maps of a pointed finite set. Essentially, the same argument can be used to establish the result of Fine and Herstein [Illinois J. Math. 2 (1958) 499-504] that the number of nilpotent n x n matrices over the finite field F-q is q(n)((n-1)). (c) 2005 Elsevier Inc. All rights reserved.